Would the effect be limited to once per turn, or can the creature attack as many times as it is damaged (multiple creatures attacking a Gravity pulled target, for example)?
Also, if this is cast on an opponent's vampire creature, would the creature heal the opponent or the caster as it attacks upon being damaged?
And no, I don't think it's too powerful given its pretty high cost.
Adrenaline+Overdrive sounds like a fun combo, though it does require three elements. Does have a potential to be particularly powerful when combined with Fire Shield, though.