me gusta la idea
An interesting point would be a Necromancer who is a "life-death dealer". For example:
1. DPS build, who is just a summoner, who gets some life/mana and spaws minions with corpses, and dot enemies. (most typical one)
2. Heal build, who is the life-death dealer, stealing essence from enemies (and doing some damage) to heal all and selected (more focus) allies, with hots.
3. Tank build, more similar to Wow Deathknight one, using bones shield/armor, drain tanking and fighting with a scythe, puting buffs/debuffs.