Necromancer is more of an enemy job. I believe the only time Necromancer was a playable job was in the GB version of final fantasy V. The only problem I see with Necromancer fitting in is that it isn't a job befitting of the general "hero" theme of the game.

One could argue that you could find an "unexpected hero" in generally what would be considered evil. Take Everquest 2 for example. It has factions for both good and evil and only evil characters may play Necromancers. Since we're in a game that's about good vs evil (for the most part) I don't think Necromancer has a place in X|V.