Man... Illidan did never die, that is one hell of a WRONG fact...
The Lich King Triumphant
Even weakened as he was, Arthas ultimately outmaneuvered Illidan and reached the Frozen Throne first. Using his runeblade, Frostmourne, Arthas shattered the Lich King's icy prison and thereby released Ner'zhul's enchanted helm and breastplate. Arthas placed the unimaginably powerful helm on his head and became the new Lich King. Ner'zhul and Arthas' spirits fused into a single mighty being, just as Ner'zhul had always planned. Illidan and his troops were forced to flee back to Outland in disgrace, while Arthas became one of the most powerful entities the world had ever known.
Currently Arthas, the new and immortal Lich King, resides in Northrend; he is rumored to be rebuilding the citadel of Icecrown. His trusted lieutenant, Kel'Thuzad, commands the Scourge in the Plaguelands. Sylvanas and her rebel Forsaken hold only the Tirisfal Glades, a small portion of the war-torn kingdom.
Dakho, not really, the only sunwell was in Dalaran, Dalaran got caged in the Defensive Sphere around the City, you should seriously play the campaign of Warcraft 3.
And Kil'Jaeden is not like Sargeras or Archimonde, btw Sargeras got never summoned, he just appeared as a ghost, not in his physical appearance, and Archimonde came with the burning legion, which opened the gate between the worlds, you cannot summon a lord of the burning legion through a caged well which can't be accessed anymore due to the indestructible sphere.
Just my two cents, and get a idea of the lore, Sargeras was never summoned beside in the time of the titans, he fought against the 4 aspects, they sealed him in the nether, same for Kil'Jaeden, Sargera's General.