Way of Dark
Thirst - Regular attacks against opponents heal you for 1/2 a heart.
Thirst really benefits a strong, front-line warrior. The Vampire needs regular melee attacks to connect in order for the ability to be useful. Encourage melee engagements by making mid-range combat unpalatable for your opponents. Good choices for secondary abilities would be Set Pitch or Overcharge. Facing off against a warrior-type? Take Rage as your secondary ability and spam your Charge Attack.
Leads to: Bloodborn or Devourer