Rule 614.9

Some effects replace damage dealt to one battle, creature, planeswalker, or player with the same damage dealt to another battle, creature, planeswalker, or player; such effects are called redirection effects. If one of those permanents is no longer on the battlefield when the damage would be redirected, or is no longer a battle, creature, or planeswalker when the damage would be redirected, the effect does nothing. If damage would be redirected to or from a player who has left the game, the effect does nothing.