Coram, the Undertaker gets +X/+0, where X is the greatest power among creature cards in all graveyards.
Whenever Coram attacks, each player mills (To mill a card, a player puts the top card of their library into their graveyard.) a card.
During each of your turns, you may play a land and cast a spell from among cards in graveyards that were put there from libraries this turn.
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