Arthas and the Dreadlords

[SalvatorThenorium]

Considering that the dreadlords — seasoned agents of the Burning Legion — already possessed vast knowledge of necromancy, mental manipulation, and political influence over the human kingdoms, along with direct access to demonic power and the Lich King (Ner'zhul) himself, was Arthas Menethil truly essential for the Legion's invasion to succeed? Or was he merely a disposable pawn, a manipulable instrument that conveniently advanced a plan the Nathrezim could have executed through other means, with different champions or strategies? — This question came to me after revisiting the Undead campaign... and honestly, everything Arthas did (or could have done) was something any dreadlord could have accomplished in his place. It really makes me think that Arthas was just a major pawn in the grand scheme of things — something clearly written into the script.

 

[deepstrasz]

Arthas was Ner'zhul's way out of the ice prison.

 

[SalvatorThenorium]

Arthas was Ner'zhul's way out of the ice prison.

Exactly, that's my point. The nathrezim are consistently portrayed as highly intelligent beings — master manipulators and schemers who operate from the shadows. Yet, throughout the story, they’re deceived in such simplistic ways that it undermines the very traits they were given. Take Arthas and Kel’Thuzad, both before and after the Frozen Throne — how did the nathrezim not know that Archimonde had died and the Legion’s invasion had failed? How did they miss Arthas’s true intentions with Kel’Thuzad from the beginning? This kind of oversight contradicts everything we’re told about them, and for me, it always felt like a break in character that just never sat right. — Like in the second mission of the Undead campaign — Tichondrius is just sitting in a village doing absolutely nothing to assist Arthas in any meaningful way. I know he gives an explanation in the same cutscene, but it still doesn’t make any real sense. The nathrezim, during the main storyline of the Undead campaign — where they’re supposedly key players on the front lines — are almost completely sidelined by the devs. It feels like their presence was an afterthought, which is disappointing given their established importance.

 

[deepstrasz]

They are not most intelligent of all. Ner'zhul and Kel'thuzad outsmarted them. Most were busy with the invasion. Mal'ganis was quickly eliminated since he was the nearest to the Lich King and directly involved with the plague. A question is why didn't the Legion do anything about that as we then see Arthas as a Death Knight talking to Tichondrious, taking orders but still. I think, as we can see in the Frozen Throne with Varimathras, that they have their own interests as well. They're devils, basically not to be confided in, treacherous.
I guess it's how the writer(s) wanted it to be, somehow the distance between Kalimdor and Azeroth being big and the Legion not having a proper intercontinental communication means. Remember that to talk to Archimonde, Kel'thuzad used a portal. Yeah, it was between planets/realms but still, something similar could be valid in the dreadlords' case.
Tichondrious did not have to do petty work. He was a commander. We see him closer to important stuff in Kalimdor when Illidan eliminates him.
It's true that the Dreadlord, is the only melee hero we don't play with/as in any of the campaigns. So, there might actually be some truth to what you wrote. Perhaps, stuff was rushed or scrapped.

 

[SalvatorThenorium]

They are not most intelligent of all. Ner'zhul and Kel'thuzad outsmarted them. Most were busy with the invasion. Mal'ganis was quickly eliminated since he was the nearest to the Lich King and directly involved with the plague. A question is why didn't the Legion do anything about that as we then see Arthas as a Death Knight talking to Tichondrious, taking orders but still. I think, as we can see in the Frozen Throne with Varimathras, that they have their own interests as well. They're devils, basically not to be confided in, treacherous.
I guess it's how the writer(s) wanted it to be, somehow the distance between Kalimdor and Azeroth being big and the Legion not having a proper intercontinental communication means. Remember that to talk to Archimonde, Kel'thuzad used a portal. Yeah, it was between planets/realms but still, something similar could be valid in the dreadlords' case.
Tichondrious did not have to do petty work. He was a commander. We see him closer to important stuff in Kalimdor when Illidan eliminates him.
It's true that the Dreadlord, is the only melee hero we don't play with/as in any of the campaigns. So, there might actually be some truth to what you wrote. Perhaps, stuff was rushed or scrapped.

Exactly... that's what I was about to bring up. The only nathrezim who truly fulfilled his role effectively was Mal'Ganis. He was directly responsible for planting the seeds of corruption in Arthas, leading him down a path of vengeance that would eventually result in his downfall. Didn't any of the other dreadlords — like Tichondrius, Balnazzar, Detheroc, or Varimathras — miss Mal'Ganis? The one who started it all in the lands of Lordaeron? Did they not even question Arthas about it? Were they unaware of his death? I've never found any answers to that...

 

[deepstrasz]

We are probably delving too intellectually deep into a video game's story.

 

[Galendor an'Kreil]

Arthas's entire campaign to Northrend was a grand spectacle staged by Nerzhul with the permission of the nathrezim in order for Arthas to become the champion of the Scourge. I think that Nerzhul convinced the Nathrezim that without Arthas, the fall of Lordaeron would be much longer and more difficult, and that the mighty champion would strengthen the Scourge and bring the Legion’s Plan closer to fruition.

Mal'ganis voluntarily participated in this spectacle. He knew that Arthas would take Frostmourne. All he didn't know was that Nerzhul would order Arthas to kill the demon. This was most likely explained to the other dreadlords as the prince's last act before completely submitting to the Scourge - or as a necessary sacrifice for the Plan to be realized.

In any case, while the Scourge carried out its part of the Plan, the dreadlords were forced to come to terms with this - but Tichondrius's attitude towards Arthas throughout the undead campaign clearly indicates that the demons do not tolerate this mortal and do not trust Ner'zhul. The apotheosis of all this is the Nathrezim conspiracy against Arthas after the fall of the Legion, when the betrayal of Ner'zhul became obvious for them.

 

[SalvatorThenorium]

Arthas's entire campaign to Northrend was a grand spectacle staged by Nerzhul with the permission of the nathrezim in order for Arthas to become the champion of the Scourge. I think that Nerzhul convinced the Nathrezim that without Arthas, the fall of Lordaeron would be much longer and more difficult, and that the mighty champion would strengthen the Scourge and bring the Legion’s Plan closer to fruition.

Mal'ganis voluntarily participated in this spectacle. He knew that Arthas would take Frostmourne. All he didn't know was that Nerzhul would order Arthas to kill the demon. This was most likely explained to the other dreadlords as the prince's last act before completely submitting to the Scourge - or as a necessary sacrifice for the Plan to be realized.

In any case, while the Scourge carried out its part of the Plan, the dreadlords were forced to come to terms with this - but Tichondrius's attitude towards Arthas throughout the undead campaign clearly indicates that the demons do not tolerate this mortal and do not trust Ner'zhul. The apotheosis of all this is the Nathrezim conspiracy against Arthas after the fall of the Legion, when the betrayal of Ner'zhul became obvious for them.

Yes... that makes sense. And speaking of this spectacle, I find the whole structure of the Cult very interesting -- from the desperate peasants after the end of the Second War to high-ranking nobles -- Do you know of any place that goes into more detail about the organization of the Cult? For example, more about the nobles who allied with Kel’Thuzad, like Baron Rivendare? I feel like the available information is always too shallow when it comes to the Cult itself -- And as for Arthas, I believe he was the main cause of Lordaeron’s downfall.

 

[deepstrasz]

Arthas's entire campaign to Northrend was a grand spectacle staged by Nerzhul with the permission of the nathrezim in order for Arthas to become the champion of the Scourge. I think that Nerzhul convinced the Nathrezim that without Arthas, the fall of Lordaeron would be much longer and more difficult, and that the mighty champion would strengthen the Scourge and bring the Legion’s Plan closer to fruition.

Mal'ganis voluntarily participated in this spectacle. He knew that Arthas would take Frostmourne. All he didn't know was that Nerzhul would order Arthas to kill the demon. This was most likely explained to the other dreadlords as the prince's last act before completely submitting to the Scourge - or as a necessary sacrifice for the Plan to be realized.

In any case, while the Scourge carried out its part of the Plan, the dreadlords were forced to come to terms with this - but Tichondrius's attitude towards Arthas throughout the undead campaign clearly indicates that the demons do not tolerate this mortal and do not trust Ner'zhul. The apotheosis of all this is the Nathrezim conspiracy against Arthas after the fall of the Legion, when the betrayal of Ner'zhul became obvious for them.

Whilst some of that can be rather inferred than proven by facts, Mal'Ganis acted like Ner'zhul was somehow superior to him or at least a force to reckon with. There's an inconsistency here we don't have clear details about. Did Mal'Ganis submit to Ner'zhul distancing himself from his nathrezim brothers?

The demons didn't care about the undead or Ner'zhul more than them being their slaves doing what they had to do. Kil'jaeden locked Ner'zhul in the ice prison and turned him into undead. The nathrezim were some of the Burning Legion's higher ranking agents (perhaps something like the SS or NKVD).
I feel Tichondrious would have never tolerated the killing of Mal'Ganis. There was no innerfighting in the dreadlord order for Mal'Ganis to be taken out for some reason and a sacrifice plan was neither obvious nor logical IMO.
Ner'zhul's defence could have been that Arthas killed Mal'Ganis in Northrend before being corrupted and becoming a Death Knight, thus the undead orc slave coming out with clean hands. But this is only a deduction, not evident or shown in the game.

The dreadlords vs Arthas in TfT is no surprise. Once they realized Ner'zhul was no longer under the Burning Legion's influence, they understood he and his lackeys (+most of the Scourge) became the nathrezim and legion's enemies. Tichondrious coming to terms with Mal'Ganis' death for Ner'zhul's intersts is like agreeing that the Lich King is an actual king (not theirs but an important force) and not the legion's subordinate. That would make the nathrezim and probably part of the legion desperate to close eyes for the sake of hurrying with the conclusion in Kalimdor. I think Kil'jaeden could have done Ner'zhul harm which even if it could have slowed the Scourge a bit it would have not stopped the legion's advance as a whole. Plus, Kil'jaeden only became weary of Ner'zhul's powers after Archimonde's demise, thus contacting Illidan to take care of the Scourge.

I think there might be quite some plotholes in the whole thing. For instance, it's funny that the Scourge did exactly what the legion wanted but that was also their downfall because Ner'zhul had foreseen it. But at the same time the legion gave so much power to the Scourge, basically almost entirely using it to decimate par of Azeroth (the continent) as well as be the main force during the siege of Nordrassil. Moreover, they simply let Kel'thuzad get Medivh's book and have him summon Archimonde thus downplaying their own powers.
It's debatable if the fall of Lordaeron would have been slower since the main idea was to use the plague to eradicate everyone. That's where I think Ner'zhul interfered in the legion's plans for himself, by using Kel'thuzad to get Arthas to eventually be his release. But if the nathrezim knew Kel'thuzad's orders, they could have understood what the undead orc was trying to do so it's quite a stretch (again, Mal'Ganis feels disconnected from the other dreadlords). It's also weird that we only know of Ner'zhul's actual plan in TfT (so perhaps initially that wasn't the idea?) but it came with a condition, that the Lich King was in danger, Illidan et al coming to get him. Otherwise, would he have still done it later without rushing?

That's why I feel we should simply take the story as it is as trying to find intricate explanations is bound to get you hit walls and go through parts of the labyrinth again.
But perhaps I might not be too fluent in all of this and have holes of my own in the argumentation.

 

[SalvatorThenorium]

Whilst some of that can be rather inferred than proven by facts, Mal'Ganis acted like Ner'zhul was somehow superior to him or at least a force to reckon with. There's an inconsistency here we don't have clear details about. Did Mal'Ganis submit to Ner'zhul distancing himself from his nathrezim brothers?

The demons didn't care about the undead or Ner'zhul more than them being their slaves doing what they had to do. Kil'jaeden locked Ner'zhul in the ice prison and turned him into undead. The nathrezim were some of the Burning Legion's higher ranking agents (perhaps something like the SS or NKVD).
I feel Tichondrious would have never tolerated the killing of Mal'Ganis. There was no innerfighting in the dreadlord order for Mal'Ganis to be taken out for some reason and a sacrifice plan was neither obvious nor logical IMO.
Ner'zhul's defence could have been that Arthas killed Mal'Ganis in Northrend before being corrupted and becoming a Death Knight, thus the undead orc slave coming out with clean hands. But this is only a deduction, not evident or shown in the game.

The dreadlords vs Arthas in TfT is no surprise. Once they realized Ner'zhul was no longer under the Burning Legion's influence, they understood he and his lackeys (+most of the Scourge) became the nathrezim and legion's enemies. Tichondrious coming to terms with Mal'Ganis' death for Ner'zhul's intersts is like agreeing that the Lich King is an actual king (not theirs but an important force) and not the legion's subordinate. That would make the nathrezim and probably part of the legion desperate to close eyes for the sake of hurrying with the conclusion in Kalimdor. I think Kil'jaeden could have done Ner'zhul harm which even if it could have slowed the Scourge a bit it would have not stopped the legion's advance as a whole. Plus, Kil'jaeden only became weary of Ner'zhul's powers after Archimonde's demise, thus contacting Illidan to take care of the Scourge.

I think there might be quite some plotholes in the whole thing. For instance, it's funny that the Scourge did exactly what the legion wanted but that was also their downfall because Ner'zhul had foreseen it. But at the same time the legion gave so much power to the Scourge, basically almost entirely using it to decimate par of Azeroth (the continent) as well as be the main force during the siege of Nordrassil. Moreover, they simply let Kel'thuzad get Medivh's book and have him summon Archimonde thus downplaying their own powers.
It's debatable if the fall of Lordaeron would have been slower since the main idea was to use the plague to eradicate everyone. That's where I think Ner'zhul interfered in the legion's plans for himself, by using Kel'thuzad to get Arthas to eventually be his release. But if the nathrezim knew Kel'thuzad's orders, they could have understood what the undead orc was trying to do so it's quite a stretch (again, Mal'Ganis feels disconnected from the other dreadlords). It's also weird that we only know of Ner'zhul's actual plan in TfT (so perhaps initially that wasn't the idea?) but it came with a condition, that the Lich King was in danger, Illidan et al coming to get him. Otherwise, would he have still done it later without rushing?

That's why I feel we should simply take the story as it is as trying to find intricate explanations is bound to get you hit walls and go through parts of the labyrinth again.
But perhaps I might not be too fluent in all of this and have holes of my own in the argumentation.

Inconsistencies in the story aren’t anything new... If they were following any kind of logic, the Forsaken should have ceased to exist the moment Arthas took the Helm of Domination again (it would’ve actually saved a good chunk of Warcraft’s storyline. Lol)

 

[deepstrasz]

Inconsistencies in the story aren’t anything new... If they were following any kind of logic, the Forsaken should have ceased to exist the moment Arthas took the Helm of Domination again (it would’ve actually saved a good chunk of Warcraft’s storyline. Lol)

While I agree with the sentiment from a certain point of view, I feel, the way they broke undead that way was creative and opened up a path for good undead (like Frostmourne's revenant guardian).
I think it's a matter of story line perspective. Whether you wanted it to have Sylvanas be a sort of Arthas clone or get a strong personality of vengeance and redemption out of her (although in the end she remained rather evil than neutral; not talking about WoW, let's not even mention that).
You could find another addition to the explanation of why she couldn't be enslaved anymore. Afterwards she could have gained enough power to keep the control web far from her or simply cut through it. Perhaps, the Lich King would have needed to focus much on her at the expense of other undead already under his influence. Another thing could be, Sylvanas was a high elf, not a mere human. Consider we don't see any reanimated night elves (directly at least; even if the high elves are somewhat different, they are still elves) and neither Quel'Thalas ones as far as I remember except for gameplay mechanics (Raise Dead/Animate Dead) and the official Sylvanas transformation. And mind you, she was turned into a banshee not a regular undead.
One can definitely come up with various explanations as why yes or no. However, once again, it is what it is and agreeing or disagreeing doesn't do much when the story overall makes sense, at least most of the time.

 

[SalvatorThenorium]

While I agree with the sentiment from a certain point of view, I feel, the way they broke undead that way was creative and opened up a path for good undead (like Frostmourne's revenant guardian).
I think it's a matter of story line perspective. Whether you wanted it to have Sylvanas be a sort of Arthas clone or get a strong personality of vengeance and redemption out of her (although in the end she remained rather evil than neutral; not talking about WoW, let's not even mention that).
You could find another addition to the explanation of why she couldn't be enslaved anymore. Afterwards she could have gained enough power to keep the control web far from her or simply cut through it. Perhaps, the Lich King would have needed to focus much on her at the expense of other undead already under his influence. Another thing could be, Sylvanas was a high elf, not a mere human. Consider we don't see any reanimated night elves (directly at least; even if the high elves are somewhat different, they are still elves) and neither Quel'Thalas ones as far as I remember except for gameplay mechanics (Raise Dead/Animate Dead) and the official Sylvanas transformation. And mind you, she was turned into a banshee not a regular undead.
One can definitely come up with various explanations as why yes or no. However, once again, it is what it is and agreeing or disagreeing doesn't do much when the story overall makes sense, at least most of the time.

Deep, what’s your honest opinion about what Warcraft has become — the story overall in recent years? Honestly, I hope Blizzard doesn’t even try to make a Warcraft IV, considering everything they've done so far. What’s your take on the story, expansions, and the general state of WoW/WarcraftIIIReForged these days?

 

[deepstrasz]

Deep, what’s your honest opinion about what Warcraft has become — the story overall in recent years? Honestly, I hope Blizzard doesn’t even try to make a Warcraft IV, considering everything they've done so far. What’s your take on the story, expansions, and the general state of WoW/WarcraftIIIReForged these days?

I feel we would tread directly into off-topic realm as we are one step in already.
This should be discussed in another thread, or rather at least two, considering the themes are not necessarily related aside the Warcraft topic.

 

[raypack]

Whilst some of that can be rather inferred than proven by facts, Mal'Ganis acted like Ner'zhul was somehow superior to him or at least a force to reckon with. There's an inconsistency here we don't have clear details about. Did Mal'Ganis submit to Ner'zhul distancing himself from his nathrezim brothers?

The demons didn't care about the undead or Ner'zhul more than them being their slaves doing what they had to do. Kil'jaeden locked Ner'zhul in the ice prison and turned him into undead. The nathrezim were some of the Burning Legion's higher ranking agents (perhaps something like the SS or NKVD).
I feel Tichondrious would have never tolerated the killing of Mal'Ganis. There was no innerfighting in the dreadlord order for Mal'Ganis to be taken out for some reason and a sacrifice plan was neither obvious nor logical IMO.
Ner'zhul's defence could have been that Arthas killed Mal'Ganis in Northrend before being corrupted and becoming a Death Knight, thus the undead orc slave coming out with clean hands. But this is only a deduction, not evident or shown in the game.

The dreadlords vs Arthas in TfT is no surprise. Once they realized Ner'zhul was no longer under the Burning Legion's influence, they understood he and his lackeys (+most of the Scourge) became the nathrezim and legion's enemies. Tichondrious coming to terms with Mal'Ganis' death for Ner'zhul's intersts is like agreeing that the Lich King is an actual king (not theirs but an important force) and not the legion's subordinate. That would make the nathrezim and probably part of the legion desperate to close eyes for the sake of hurrying with the conclusion in Kalimdor. I think Kil'jaeden could have done Ner'zhul harm which even if it could have slowed the Scourge a bit it would have not stopped the legion's advance as a whole. Plus, Kil'jaeden only became weary of Ner'zhul's powers after Archimonde's demise, thus contacting Illidan to take care of the Scourge.

I think there might be quite some plotholes in the whole thing. For instance, it's funny that the Scourge did exactly what the legion wanted but that was also their downfall because Ner'zhul had foreseen it. But at the same time the legion gave so much power to the Scourge, basically almost entirely using it to decimate par of Azeroth (the continent) as well as be the main force during the siege of Nordrassil. Moreover, they simply let Kel'thuzad get Medivh's book and have him summon Archimonde thus downplaying their own powers.
It's debatable if the fall of Lordaeron would have been slower since the main idea was to use the plague to eradicate everyone. That's where I think Ner'zhul interfered in the legion's plans for himself, by using Kel'thuzad to get Arthas to eventually be his release. But if the nathrezim knew Kel'thuzad's orders, they could have understood what the undead orc was trying to do so it's quite a stretch (again, Mal'Ganis feels disconnected from the other dreadlords). It's also weird that we only know of Ner'zhul's actual plan in TfT (so perhaps initially that wasn't the idea?) but it came with a condition, that the Lich King was in danger, Illidan et al coming to get him. Otherwise, would he have still done it later without rushing?

That's why I feel we should simply take the story as it is as trying to find intricate explanations is bound to get you hit walls and go through parts of the labyrinth again.
But perhaps I might not be too fluent in all of this and have holes of my own in the argumentation.

About the

Moreover, they simply let Kel'thuzad get Medivh's book and have him summon Archimonde thus downplaying their own powers.

part:
Apparently, apart from the magical skillset and knowledge, which I've always assumed that Tichondrius has had, a mortal being was required for the ritual. That is where Kel'Thuzad comes in play. This happens a few missions after Kel'Thuzad is revived and boasts how he has been granted eternal life, but he's not a demon such as the dreadlords. I guess that's kind of the reason.
According to Google:
Mortal Presence:
Demons often require a mortal's presence to manifest in Azeroth, and Kel'Thuzad, as a lich, provided that necessary link.

The Legion had an incredibly good plan for the invasion. I mean if you go in-depth, it's Palpatine level typa shi. AND the fact that Ner'zhul outplayed them is insane. He knew he had to help them come into Azeroth in order to beat them and free himself.

I agree about the Mal'Ganis stuff. It always felt weird to me how disconnected he seemed from the rest of the dreadlords. Tichondrius mentions him once and that's it.

 

[deepstrasz]

Apparently, apart from the magical skillset and knowledge, which I've always assumed that Tichondrius has had, a mortal being was required for the ritual. That is where Kel'Thuzad comes in play. This happens a few missions after Kel'Thuzad is revived and boasts how he has been granted eternal life, but he's not a demon such as the dreadlords. I guess that's kind of the reason.

Is there any ingame part where this is told/obvious?
Also, Kel'Thuzad was definitely not mortal anymore after becoming a lich and it was in that form he made the summoning. Kel'Thuzad was not Medivh. He was however, an ex-kirin torian and possibly knew the language in which the book was written. However, that's still a stretch. I would assume that after 10k years the Burning Legion would have known how to get to Azeroth without any native help. Mind you, the nathrezim and others got there by themselves.
Would have somewhat made sense if it had been a sacrifice, like the lich dying afterwards or something. There is no specification that only non-demons can do the summoning, implying that a demon can't summon a demon or the like. Besides, whether the undead are different than demons to some regard, they are a product of theirs or their dark magic. It was the demons, after all, who taught the orcs to use necromancy and all that.

He knew he had to help them come into Azeroth in order to beat them and free himself.

Yeah. That's the oddity or rather far fetched part. Arthas or anyone else (the manual even says there were more death knights around Ner'zhul) ESPECIALLY Kel'Thuzad could have been used as a vessel of freedom without needing to get the Burning Legion on Azeroth risking his plan and everything. It was Kil'Jaeden who imprisoned Ner'Zhul not Archimonde, so getting rid of Archimonde didn't exempt the undead orc from the actual torturer.

 

[raypack]

Is there any ingame part where this is told/obvious?
Also, Kel'Thuzad was definitely not mortal anymore after becoming a lich and it was in that form he made the summoning. Kel'Thuzad was not Medivh. He was however, an ex-kirin torian and possibly knew the language in which the book was written. However, that's still a stretch. I would assume that after 10k years the Burning Legion would have known how to get to Azeroth without any native help. Mind you, the nathrezim and others got there by themselves.
Would have somewhat made sense if it had been a sacrifice, like the lich dying afterwards or something. There is no specification that only non-demons can do the summoning, implying that a demon can't summon a demon or the like. Besides, whether the undead are different than demons to some regard, they are a product of theirs or their dark magic. It was the demons, after all, who taught the orcs to use necromancy and all that.

Yeah. That's the oddity or rather far fetched part. Arthas or anyone else (the manual even says there were more death knights around Ner'zhul) ESPECIALLY Kel'Thuzad could have been used as a vessel of freedom without needing to get the Burning Legion on Azeroth risking his plan and everything. It was Kil'Jaeden who imprisoned Ner'Zhul not Archimonde, so getting rid of Archimonde didn't exempt the undead orc from the actual torturer.

About the 1st part: in-game there is no mention about that, I just googled it
And yeah I agree.

About the most interesting 2nd part: I must say that the Legion being defeated made it possible for Arthas reaching Ner'zhul and freeing him, since before and after Archimonde's summoning (but before his defeat), the dreadlords were constantly monitoring the Lich King. They would have never allowed Arthas to just go to Northrend and free Ner'zhul.
So, the major blow of defeat that was dealt on the Legion was necessary in my opinion.

 

[deepstrasz]

About the most interesting 2nd part: I must say that the Legion being defeated made it possible for Arthas reaching Ner'zhul and freeing him, since before and after Archimonde's summoning (but before his defeat), the dreadlords were constantly monitoring the Lich King. They would have never allowed Arthas to just go to Northrend and free Ner'zhul.

Theory IMO. Ner'zhul already got rid of the closest nathrezim and before that, had Arthas get the blade. Tichondrious only appears way after and in Lordaeron, so Ner'zhul could have merged with Arthas right there at the end of the RoC Human campaign. He (the Lich King alone) was powerful enough to get rid of all nathrezim and demons already on Azeroth. He was not controlled by the dreadlords but only supervised. And as we saw, without Kel'Thuzad, the legion would have been out of Azeroth for who knows how much time while the Scourge could have gotten the best of the human lands and more to gain even more ground. Then the battle would have possibly been between the undead and the rest of the living (Kalimdor included). The legion could have waited that out and come after somehow fighting the winning faction, the living or the undead. If the undead won, it would have been easier to get control of some against the Lich King while the living required corruption and other means to be turned against itself. Whichever case, Ner'zhul would not have been fully protected from Kil'Jaeden's wrath while still in the prison. So, having mobility early on (i.e.) through Arthas would've been ideal.
You might say that Ner'zhul foresaw Archimonde's demise and used this opportunity to cripple both the living and the demons, however, due to the invasion, the living got stronger by uniting. So, it's quite debatable. IMO, the best choice would've been to get a vessel early on and not let the demons get to Azeroth in the first place since they apparently couldn't invade without internal help.

 

[SalvatorThenorium]

Theory IMO. Ner'zhul already got rid of the closest nathrezim and before that, had Arthas get the blade. Tichondrious only appears way after and in Lordaeron, so Ner'zhul could have merged with Arthas right there at the end of the RoC Human campaign. He (the Lich King alone) was powerful enough to get rid of all nathrezim and demons already on Azeroth. He was not controlled by the dreadlords but only supervised. And as we saw, without Kel'Thuzad, the legion would have been out of Azeroth for who knows how much time while the Scourge could have gotten the best of the human lands and more to gain even more ground. Then the battle would have possibly been between the undead and the rest of the living (Kalimdor included). The legion could have waited that out and come after somehow fighting the winning faction, the living or the undead. If the undead won, it would have been easier to get control of some against the Lich King while the living required corruption and other means to be turned against itself. Whichever case, Ner'zhul would not have been fully protected from Kil'Jaeden's wrath while still in the prison. So, having mobility early on (i.e.) through Arthas would've been ideal.
You might say that Ner'zhul foresaw Archimonde's demise and used this opportunity to cripple both the living and the demons, however, due to the invasion, the living got stronger by uniting. So, it's quite debatable. IMO, the best choice would've been to get a vessel early on and not let the demons get to Azeroth in the first place since they apparently couldn't invade without internal help.

I think the dreadlords are demons of a lower rank compared to an Draenei corrupted by Sargeras, which is why their arrival into the world is less complex -- Logically speaking, they could have also existed during the Second War, influencing the orcs... at least that’s what I believe. It really doesn’t make much sense for them to require a full summoning, but there must be some connection related to power levels or something like that, i also believe that, at that point in the story, there was no way to avoid performing the ritual - They would’ve had to face at least three dreadlords, including Varimathras, just to abandon the summoning of Archimonde...

 

[knight26]

Yes... that makes sense. And speaking of this spectacle, I find the whole structure of the Cult very interesting -- from the desperate peasants after the end of the Second War to high-ranking nobles -- Do you know of any place that goes into more detail about the organization of the Cult? For example, more about the nobles who allied with Kel’Thuzad, like Baron Rivendare? I feel like the available information is always too shallow when it comes to the Cult itself -- And as for Arthas, I believe he was the main cause of Lordaeron’s downfall.

About this part, play Mathaias cronicles, update by Med.mapguy.
It portrays a more realistic approach to the cult's formation. Many of the cultists are actually human/living. They turned to necromancy merely as a means of survival, set on revenge to the orcs.
It is non-canon, but the stories told are what happens in other places during the main invasion.

 

[deepstrasz]

I think the dreadlords are demons of a lower rank compared to an Draenei corrupted by Sargeras, which is why their arrival into the world is less complex -- Logically speaking, they could have also existed during the Second War, influencing the orcs... at least that’s what I believe. It really doesn’t make much sense for them to require a full summoning, but there must be some connection related to power levels or something like that, i also believe that, at that point in the story, there was no way to avoid performing the ritual - They would’ve had to face at least three dreadlords, including Varimathras, just to abandon the summoning of Archimonde...

Draenei->Eredar is a WoW thing. Let's not mix things up. The nathrezim are actually the last straw which drew Sargeras mad and turned him to the demon side (see RoC manual). Both Eredar and Nathrezim were one of the most powerful demons the titan encountered. The first used corrupting chaotic magics to enslave and turn creatures into demons while the second made whole nations fight among themselves through manipulation and possessed them. It's true that it seems Sargeras defeated the nathrezim much easier. He also chose two eredar as his right and left hands. However, the nathrezim were more rebellious and libertine, requiring Kil'jaeden to enslave them becoming his elite guards and agents. Archimonde, had the pit lords under him. So, while lower ranking, not really that lesser. You're right that they're not above the eredar, obvious from the game as well.
So I guess it's like the mouse can get through the small hole to the other side but the elephant although strong can't break the wall and evidently can't fit through the hole.

To note though, that only the nathrezim seem to be able to circulate from planet/twisting nether to planet without requiring a summoning ritual. But frankly, we don't know since when these nathrezim are on Azeroth. Might they be since War of the Ancients?
Also, the orcs required a portal to get to Azeroth and back. Gul'dan orderd the building of it on Draenor and uses his powers to make it work. Before that though, Medivh made the rift between the two worlds.

Three dreadlors is nothing. Remember that Sylvanas defeated them and the Lich King is much stronger (or so we think? xD). Anyways, Varimathras, Balnazzar and Detheroc were not present in RoC. The original brothers were Tichondrious, Mal'Ganis (debatalbe, since we only see him with the Scourge), Anetheron and Mephistroth. Of these all die except Mephistroth who did not come during the siege of Kalimdor and does not appear in TfT.

 

[SalvatorThenorium]

Draenei->Eredar is a WoW thing. Let's not mix things up. The nathrezim are actually the last straw which drew Sargeras mad and turned him to the demon side (see RoC manual). Both Eredar and Nathrezim were one of the most powerful demons the titan encountered. The first used corrupting chaotic magics to enslave and turn creatures into demons while the second made whole nations fight among themselves through manipulation and possessed them. It's true that it seems Sargeras defeated the nathrezim much easier. He also chose two eredar as his right and left hands. However, the nathrezim were more rebellious and libertine, requiring Kil'jaeden to enslave them becoming his elite guards and agents. Archimonde, had the pit lords under him. So, while lower ranking, not really that lesser. You're right that they're not above the eredar, obvious from the game as well.
So I guess it's like the mouse can get through the small hole to the other side but the elephant although strong can't break the wall and evidently can't fit through the hole.

To note though, that only the nathrezim seem to be able to circulate from planet/twisting nether to planet without requiring a summoning ritual. But frankly, we don't know since when these nathrezim are on Azeroth. Might they be since War of the Ancients?
Also, the orcs required a portal to get to Azeroth and back. Gul'dan orderd the building of it on Draenor and uses his powers to make it work. Before that though, Medivh made the rift between the two worlds.

Three dreadlors is nothing. Remember that Sylvanas defeated them and the Lich King is much stronger (or so we think? xD). Anyways, Varimathras, Balnazzar and Detheroc were not present in RoC. The original brothers were Tichondrious, Mal'Ganis (debatalbe, since we only see him with the Scourge), Anetheron and Mephistroth. Of these all die except Mephistroth who did not come during the siege of Kalimdor and does not appear in TfT.

This whole thing about eredar, draenei, and man'ari is really confusing to me... I'm not sure if Archimonde is an man'ari because he still looks like an uncorrupted one. Can you explain it to me? The eredar are the original race, and when they moved to Draenor they became the draenei, and the man'ari are the corrupted eredar — is that it?

 

[Galendor an'Kreil]

This whole thing about eredar, draenei, and man'ari is really confusing to me... I'm not sure if Archimonde is an man'ari because he still looks like an uncorrupted one. Can you explain it to me? The eredar are the original race, and when they moved to Draenor they became the draenei, and the man'ari are the corrupted eredar — is that it?

Back in WC3, eredar and draenei are completely different races. Eredar are a race of diabolical warlocks who confronted Sargeras even before his madness, and draenei are natives of Draenor where they lived at least 5 thousand years (wc2 handbook).