Moonlit Assassin

Ambush {2}{b}{b} (Whenever one or more creatures attacks you, if this card is in your hand, you may play it at instant speed for its Ambush cost. If
you do, return it from the battlefield to your hand at the end of combat.)
When Moonlit Assassin enters the battlefield you may sacrifice a creature, if you do then target opponent also sacrifices a creature.
There were...collateral losses.