Darth Erebos

Darth Erebos was a human from the planet Alderaan. He would become a Dark Lord of the Sith in his late 30's and lead an attack on the Jedi on every one of their worlds. Each one of the attacks would be thwarted. Erebos would kill all but one member of the Jedi council before Filose Naj came to the rescue and killed the Dark Lord, decapitating him.