Originally posted by City Hunter
Technically, he WAS a Sith Lord and left them. The topic starter's question is who was the most powerful Force User who was NEVER a Sith(Nihilus WAS a Sith) or Jedi. 😉
Well, it'd be Kar Vastor then since he manhandled Mace Windu, something the so-called most powerful Sith Lord couldn't do.