Yeah I didn't have nearly enough edits to be able to vote on that but I agree about Zorc being PE since he clearly understood darkness and how he's empowered by it.
While I'm here I might as well say the only other villain in the show even worth considering for anything other than Villainous Benchmark is The Great Leviathan/Orichalcos God but I'd have to rewatch season 4 and I'm not sure where it'd end up (Probably NPE since it's kind of a generic doomsday villain and all we know is it brainwashed Dartz and is made of evil but his motivations and goals are clear). All other villains including Pegasus (whose actions are nothing compared to Bakura or Marik despite having just as many resources), Noah, Dartz (Dartz doesn't really belong anywhere since he was possessed/brainwashed the entire time) are obviously Villainous Benchmark.