Kil'jaeden is the last boss in the Sunwell Plateau raid instance, and the final boss of The Burning Crusade expansion. Anveena, Kalecgos, and the blue dragonflight play a role in this encounter. Since the Sunwell Plateau instance was revealed, Kil'jaeden was the most powerful boss in the game pre-WotLK. On May 20, 2008, the 3rd gate of the Sunwell Plateau was brought down on US Servers unlocking the encounter.