PASSIVE: Rengar stores 50% of the post-mitigation damage he has taken in the last 1.5 seconds as grey health on his health bar, increased to 100% of damage taken from monsters.
ACTIVE: Rengar lets out a battle roar, dealing magic damage to nearby enemies and 65 − 130 (based on level) bonus magic damage to monsters, and healing himself for the amount of grey health.
EMPOWERED ACTIVE: Battle Roar's magic damage is modified and additionally cleanses Rengar of all crowd control.