The Eye of Eternity (also known as EoE) is the final instance of the Nexus in which the final (and only) boss is the blueDragon Aspect, Malygos. The fight against Malygos is comparable to the fight against Onyxia in that he is a solo raid boss housed within his own instance.
The Nexus, Coldarra
From within the safety of his personal domain, the Eye of Eternity, Malygos coordinates a crusade to reestablish his dominance over the arcane energies coursing through Azeroth. In his eyes, the foolish actions of the Kirin Tor and other mortal magi have plunged the world into chaos, and the abuse of their powers will no longer be tolerated. Threatened by the Spell-Weaver's brutal tactics, the Kirin Tor has allied itself with the red dragonflight. Together, the two groups closely observe Malygos, searching for a way to thwart his campaign and strike out at the Aspect of Magic, but thus far the elusive Spell-Weaver has proven difficult to engage.
At Wyrmrest Temple, the ancient meeting ground of the dragonflights, Alexstrasza and the ambassadors of other flights have discussed Malygos' recklessness and reluctantly concluded that he is beyond the point of salvation. With the red dragons' assistance, Azeroth's heroes may be able to accomplish what has formerly been unthinkable: challenging the Spell-Weaver from inside the Eye of Eternity. Sustaining the safety of Azeroth depends on Malygos' defeat, but his end will also herald a new age: a world of unguarded magic, absent of the Dragon Aspect powerful enough to watch over it.
The Nexus, a dungeon hub, is an ancient ice fortress found in the center of Coldarra, in Northrend's Borean Tundra. It is a column of magical energy surrounded by levitating earth-covered rings with ice caves underneath. The Nexus is an extensive series of caves and tunnels that riddles Coldarra, containing wings leading to two 5 man dungeons and one 25 man raid.
The Eye of Eternity is the final instance and the only raid of The Nexus, in which players will be able to defeat the blue dragon aspect Malygos.