This is the creature schtick of the same name, Feng Shui, p 124.

You gain additional vitality by drinking the blood of humans or other sentient beings. You have a specialized body feature that allows you to draw blood from living victims. Examples might include hollow fangs, grasping mouths on the palms of your hands or dozens of little suckers on your torso. If you have the creature abilities Abysmal Spines or Tentacles these can be your feeding equipment. There is also a special Blast, Blood Gout, that works well with Blood Drain.

When you hit an opponent with a close combat attack, and manage to wound him, you may ignore the Wound points you inflict, having some special effect instead. This still takes out an unnamed character.

For each schtick you spend you can take one of the following effects. You can only use one at the time. It s possible to combine them using Dual Attack or some other special power.

Action Value Gain

Choose a skill you and your victim have in common. You gain a +1 bonus to your Action Value for this skill until the end of the session; your opponent suffers a -1 penalty to his Action Values for the same period. This effect may be used repeatedly on the same victim, but no skill can be modified by more than ±3.

Attribute Gain

Your victim loses one point of a secondary attribute decided upon when the power is bought; you gain this point. This effect may be used repeatedly on a named victim, but no attribute can be modified by more than ±5. If you take Attribute Gain twice, you get to select a primary attribute.

Fortune Drain

You gain one of the victim's unspent Fortune points; victim loses a point. Has no effect on unnamed characters or those who currently have no Fortune points.

Life Drain

You steal Wound points equal to your attack Outcome; you heal these points, while the target loses them. There is no way to save or store up extra Wound Points.

Magic Drain

You gain one of the victim's unspent Magic points; victim loses a point. Has no effect on unnamed characters or those who currently have no Magic points.

Memory Drain

You acquire the memories of the victim. These fade at the end of the session. Until the end of the session your victim is haunted by disturbing nightmares, becomes emotionally distraught and is subject to unpredictable memory lapses and horrific hallucinations. There is no point in doing this to the same victim twice in a session.

Voice Gain

You can now mimic the voice and speech pattern of your victim with complete accuracy and may continue to do so until he end of the session. Use Creature Powers instead of Deceit for such stunts, usually with a bonus. There is no point in doing this to the same victim twice in a session.