Corel Damen Firilith
The one, the only Eldritch historical boogeyman.
He was a mind-mage, the powers drove him mad, he started killing and Jerisa deployed an army against him, which he destroyed. Then he killed himself, or was tricked into doing so. It involved a woman. (Stories differ on the exact details.)
When the attacks of the chimera and basilisks were threatening the Eldritch with extinction, Jerisa asked Corel to undergo a secret procedure to increase his mind powers. He came out of it changed, and suffering, but employed his powers against the beasts succesfully. He became a hero to the people, which made Jerisa jealous, so she told Corel that he had killed Elsabet in one of his fits, so he killed himself. Then Jerisa spread the tales about the powers driving him mad and him killing all the people (who had actually been killed by beasts).
Elsabet says she had Corel's daughter and hid her by passing her off as someone else's.