A knight/whatever that has a good(heavenly), neutral(mortal?), and evil(demonic) talent tree. It would be the only real choice because they dont have the pally and necro. Diablo 3 must have this as the 4th and some sort of ranged/whatever for the 5th.
The reason he would be fighting evil if he was evil alligined is because he believes in balance as the nec did.
I know it has been done with many games such as fable and oblivion but Diablo is the ultimate struggle between good and evil.
Please post your ideas about this.
It doesn't have to be the only option, they just have to be creative like I know they are.