So Zurgo does two red things, a white thing, and a black thing
Avacyn breaks games in seconds
Value: Varies wildly based on the Pokmon
There are tons of ways to get lands into your graveyard in green, whether its sacrificing, cycling, or milling (including dredge), and when the melded Titania, Gaea Incarnate enters the battlefield, any lands in your graveyard are put on your battlefield tapped
In either case, the deck needs tricky defenses to get to that point, since its creatures can't stand up to the format's biggest beaters
Shelob, Dread Weaver checks decks that like to sacrifice creatures and bring them back, but unlike other similar cards like Kalitas, Traitor of Ghet, Shelob has a mechanism to pass through the big Spider and deposit an exiled creature back in its controllers graveyard