It was Spock, the Romulan traitor who sold out and destroyed his and GR's universe. The fact that he saw the Medusan and other things is more than enough proof that he's crazy, and greedy.
A Romulan Daniels was also another good choice as if he was trying to ethnically purify himself by changing his past. He had his ears bobbed is all. But an evil alternate future Spock explains it pretty well. All too well.
Someone else mentioned Ziggy. That was pretty good too.
The enemy of my enemy is my friend. Me being my own worst enemy.