Cthulhu, the Aeons Torn

Cthulhu, the Aoens Torn can't be countered.
When you cast Cthulhu, take an extra turn
after this one.
Flying, protection from colored spells,
annihilator 6
When Cthulhu is put into a graveyard
from anywhere, its owner shuffles his or her
graveyard into his or her library.