Coram, the Undertaker

Coram, the Undertaker gets +X/+0, where X is the greatest power among creature cards in all graveyards.
Whenever Coram attacks, each player mills 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.

Jarad's Orders

Search your library for up to two creature cards and reveal them. Put one into your hand and the other into your graveyard. Then shuffle.

Sol Ring

Lord of Extinction

Lord of Extinction's power and toughness are each equal to the number of cards in all graveyards.