Arrows of Justice

Instant

Arrows of Justice deals 4 damage to target attacking or blocking creature.

2013-01-24:
An “attacking creature” or “blocking creature” is one that has been declared as an attacker or blocker this combat, or one that was put onto the battlefield attacking or blocking this combat. Unless that creature leaves combat, it continues to be an attacking or blocking creature through the end of combat step, even if the player it was attacking has left the game, the planeswalker it was attacking has left combat, or the creature or creatures it was blocking have left combat, as appropriate.
2013-01-24:
Arrows of Justice may be cast during the end of combat step, after combat damage has been dealt.