Kael'thas Sunstrider, Lord of the Blood Elves, is the fourth and final boss encounter of the Eye. He is accompanied by his council of four advisors: Thaladred the Darkener, Master Engineer Telonicus, Grand Astromancer Capernian and Lord Sanguinar. He spawns seven powerful legendary items which you have to fight, defeat and then equip in order to defeat Kael'thas. These items are usable only during the encounter; reseting the encounter, wiping, or releasing to the graveyard will cause them to desummon.

He is famous for dropping Ashes of Al'ar, one of the most popular mounts in the game.

This NPC can be found in Tempest Keep.