Hey, played through the map in its entirety - all the secrets found too. Pretty fun map!
I agree with the others, I was constantly crashing until I lowered my particle settings to Low.
Some things to note: a few grammatical and spelling errors here and there - the spells you receive are shown to have two hotkeys (the original and the QWER, with only QWER being the one to work). I believe this is due to Reforged automatically setting the hotkeys to display, rather than needing to manually plug them like pre-Reforged WC3 mapping.
I think the fog was a bit too overbearing, especially zoomed out. Even when zoomed in it was a slight nuisance; not a deal breaker but it certainly wasn't nice to look at. I think the gameplay at the start can be slightly dull, and it's probably due to things like slow mana regen and not a lot of spells at your disposal. By the mid to late game it does feel a bit more fun to deal out constant damage. The slow mana regen is offset by the Duskwood Wand, but even then it isn't by a substantial amount. It isn't until the later game where mana becomes virtually a non-issue.
Screams of Pain (the third ability) is a bit weak in my opinion. I understand that its use mostly draws from the debuff it applies to enemies, but due to that there isn't really much of a reason to pick it over Carrion Swarm in the start - especially since you're trying to conserve mana in the beginning. The spell you get from the fat dreadlord guy (forgot his name) Wrathful Eye was a nice addition. I wasn't able to access one secret (the Doril zombie guy) until I had that spell, by spawning it behind the trees to access the area. Honestly, I was not sure at all how to get to that area otherwise. I was also able to bug into another secret protected by a magic wall by using Wrathful Eye to provide vision and letting me Blink inside. You probably know what area this is so that's a big bug I'd say.
I'd also like to suggest to keep the Boat mechanic of going into the Lord's town as it's an easy way to go from the Duke's Keep and into the town rather than walking all the way back. I suppose there isn't much reason to go back once you've reached the Keep, but it would be nice to have as I did have to go back to look for secrets.
Terrain is great! Places feel lived in and have a decent amount of doodads. The metroidvania-esque way of looping around by unlocking previously inaccessible areas is cool - though I have to point out that I think two areas were really vague in how you can enter them (the fat dreadlord area and the Doril zombie area). Otherwise it's very fun to explore. The map does a great job of making the player use the Blink ability. However, I do wish it had less of a cooldown. I'd also suggest to remove Divine Shield from the final boss, I think a mechanic like the comment above me provided by Angzt said would be cool to replace it. Divine Shield is just usually a pain to fight against.
Overall, pretty fun 1 hour map. Exploration was clearly the focus here, and that's great because I think in most games exploration is definitely one of the most fun aspects (if done correctly, which it is here). Great job!
4/5!