felix hatake
If kakashi became evil and joined the akatsu and was teamed up with itachi, who could beat them?
WARNING SPOILER: (It explains Itachi was never evil)
Itachi isn't evil,
he was forced by the village orders to kill his family because they were going to start a civil war. He didn't kill his brother because he felt like he just couldn't but he was suppose to. Then ya, Sasuke finds that out sometime AFTER he kills Itachi from Tobi. So basically Sasuke has no family, and killed the only other family member he had for revenge.
Itachi went into the akatsu because he wanted to protect Sasuke and Konaha. Sasuke didn't know any of it till Tobi told him, and the part I'm not sure about is the part were Itachi gave him his sharugan to protect Sasuke from Tobi then Tobi makes Sasuke stay evil.