DESC: Your people need or simply enjoy the blood of other creatures. Draining the blood will allow you to gain the hit points the opponent had and add them to your own. If this amount is more than what your max hit points are, then they are added as temporary hit points that you lose at a rate of 1 per 3 rounds.
While draining blood the target can still fight back and so must be incapacitate in some fashion. You drain at a set rate on the round after you make contact.