Undead antagonist

[maniacalmojo]

I am running a 3.5 game and the BBEG is going to be an undead cleric with a scyth and a raven familiar. The goal is to have him work for a god to try and balance the world (he is true neutral) but that involves the killing of many people.

Any way someone can think of to flush out this concept or to introduce it to a campaign?