Darth Nihilus, Lord of Hunger

When Darth Nihilus, Lord of hunger enters the
battlefield, sacrifice x creatures. You gain x life
and draw x cards, where x is equal to the amount
of creatures sacrificed this way.
If Darth Nihilus, Lord of hunger would be exiled,
removed from the game, or put into a graveyard,
put him into your library, then shuffle it.