Read rules for Ulamog, the Infinite Gyre
When you cast this spell, destroy target permanent.
Indestructible
Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents of their choice.)
When Ulamog is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.
10/10
: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")