Ebon Arrow (CRMS-EN069) - Crimson Crisis Unlimited

Activate only by selecting 1 face-up monster you control. Until the End Phase it loses 500 ATK. When the selected monster attacks a Defense Position monster whose DEF is lower than its ATK, inflict the difference as Battle Damage to your opponent. When the selected monster destroys a monster by battle inflict damage to your opponent equal to destroyed monster's original DEF.