Rivalkys, World's Sacrifice

Trample, annihilator 2
When Rivalkys, World's Sacrifice enters the
battlefield, if it was cast, gain control of target
creature an opponent controls. Untap it. It gains
haste until end of turn. Sacrifice it at the
beginning of the next end step.
When Rivalkys, World's Sacrifice is put into it's
owner's graveyard from anywhere, it's owner
shuffles their graveyard into their library.