Riverchurn Monument (First-Place Foil) [Aetherdrift]

Cost: 1 U 1 , T : 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 U U , T : Any number of target players each mill cards equal to the number of cards in their graveyard. (Activate each exhaust ability only once.