How does Bishop of Binding work with Panharmonicon? It triggers twice when it enters the battlefield, exiling two creatures, but then the attack trigger says, "the exiled card" (singular). Thanks!
X will be equal to the combined power of the two exiled cards because of this rule:
607.3 If, within a pair of linked abilities, one ability refers to a single object as “the exiled card,” “a card exiled with [this card],” or a similar phrase, and the other ability has exiled multiple cards (usually because it was copied), the ability refers to each of the exiled cards. If that ability asks for any information about the exiled card, such as a characteristic or converted mana cost, it gets multiple answers. If these answers are used to determine the value of a variable, the sum of the answers is used. If that ability performs any actions on the exiled card, it performs that action on each exiled card.