trying to remember an episode of this show

I've always been a fan of this show, but the episode that got me interested is one I don't know the name of, and wish I did. Zorn gets a lot of focus as he develops his special powers, and temporarily goes evil, back to good before the episode is over though. Someone wa smanipulating him he didnt just choose evil randomly, but my memory is sketchy. Does anyone else remember this episode/know which one it is? It's been driving me nuts for a while (took me long enough as is just to remember the show's name xD).