i so thought this was going to be a thread on whether or not Sasuke is a villain, but...

The OP theory... just seems crazy! An imposter Itachi, yet Itachi acting under super mysterious orders to keep Sasuke thinking it was him... Sorry, I just don't buy it.

The guy's motivation for keeping Sasuke alive aren't clear, but him suggesting that Sasuke kill his best friend, plus the fact that Itachi apparently did this, then killed his parents and clan, and the fact that he's a key member in a group aiming for World Domination Mwahahaha! TM. suggests, somewhat strongly, that he is perhaps one of the worst villains in all of Naruto.