805.10c

Any rule, object, or effect that refers to an “attacking player” refers to one specific attacking player, not to all attacking players. If an ability of a blocking creature refers to an attacking player, or a spell or ability refers to both a blocking creature and an attacking player, then unless otherwise specified, the attacking player it’s referring to is the player who controls the attacking creature that blocking creature is blocking. If a spell or ability could apply to multiple blocking creatures, the appropriate attacking player is individually determined for each of those blocking creatures. If there are multiple attacking players that could be chosen, the controller of the spell or ability chooses one.