Grakon

Grakon was an ancient Sith Lord and later became the first Mancer Lord. He was the founder of the Mancer religion and became the most powerful Mancer Lord in the history of the order, even after being persecuted by the Sith for leaving their order. It is unknown how Grakon discovered this power, but many Sith left to join him to discover how to use the force to their whim.

Grakon would be killed during a solo attack on his enemies, in which he returned to Korriban to attempt and slaughter all the Sith who were there. He would fail, after taking down nearly the entire academy, and would be killed by one of the first Sith Lords, King Adas

Centuries after his death, he felt the Mancers were returning to the galaxy. He called a Lord named Brutalidon to take over his body. With his soul in a new shell, Grakon would destroy the weak Sith on Korriban and nearly the Jedi on Coruscant before falling once more.