Don't forget about souleater, classic signature skill. Sacrifice HP for DMG to target, all target. Maybe that will be DRK's AoE threat generator. As a tank, I think it would need a high HP base if will sacrifice HP for moves, but that would seem a bit imbalanced and my PLD would cry. He likes high HP and is jealous of my WAR...

All we can do is speculate and wait till they release confirmed information.