Riverchurn Monument (Extended Art) (DFT-381) - Aetherdrift: (Extended Art)

{1}, : Any number of target players each mill two cards. (Each of them puts the top two cards of their library into their graveyard.)
Exhaust — {2}, : Any number of target players each mill cards equal to the number of cards in their graveyard. (Activate each exhaust ability only once.)