Kosmos, Titan of Gods' Denial

When Kosmos, Titan of Gods' Denial, enters the battlefield, sacrifice it unless it escaped.
Whenever Kosmos enters the battlefield or
attacks, put the top three cards of your library
into your graveyard. Then return a card from
your graveyard to your hand.
Escape —{u}{u}{b}{b}, Exile five other cards from
your graveyard. (You may cast this card from your
graveyard for its escape cost.)