Cthulhu, Lord of the Abyss

Flying.
Players do not lose the game due to drawing
from an empty library.
When Cthulhu, Lord of the Abyss deals combat
damage to a player, until it transforms, exile that players library.
Cthulhu, Lord of the Abyss gets +3/+3 for each
player who has no cards in their library.
If Cthulhu, Lord of the Abyss would leave the battlefield transform it instead.