29 Sept 2017
The creature cards may come from different graveyards.
29 Sept 2017
In a multiplayer game, if a player leaves the game, all cards that player owns leave as well. If you leave the game, any creatures you control from Boneyard Parley’s effect are exiled.
29 Sept 2017
You (not your opponent) choose which pile to put onto the battlefield and which to return to graveyards.
29 Sept 2017
In multiplayer games, you choose an opponent to separate the cards when the ability resolves. This doesn’t target that opponent. Because the cards are revealed, all players may see the cards and offer opinions.
29 Sept 2017
A pile can have no cards in it. In this case, you’ll choose whether to put all the exiled cards onto the battlefield or into graveyards.