Dark knight Khanis

Khanis, an immortal who started an event in the past called the war of wrath, where she led the despotic races against the Phalzion dynasty, and this war lasted for a thousand years until the hero of Brandasion rose up and 'Killed' her, but in the process died themselves, but the high lords of Phalzion found that she could not die, so while she was incapacitated they locked her away in the Crimson vaults, deep in the lowest levels where you can feel the beating heart of the world locked in unbreakable Phorash metal cuffs, Ghu'rash lances imbedded in her back and locked within a stone cube in the middle of the room, she was to remain there and be forgotten for all time
(The world basically believes that she died in the last battle of the war of wrath).