It That Betrays

Annihilator abilities trigger and resolve during the declare attackers step. The defending player chooses and sacrifices the required number of permanents before they declare blockers. Any creatures sacrificed this way won’t be able to block.

When the second ability resolves, you must return the card to the battlefield, even if you don’t want to.

If an opponent sacrifices a nontoken permanent as part of paying the cost of a spell or ability, the second ability triggers and goes on the stack on top of it. This ability will resolve, causing you to return the card to the battlefield before the other spell or ability resolves.

If the sacrificed permanent that caused the second ability to trigger somehow leaves the graveyard before the ability resolves (possibly because it was returned to the battlefield by the ability of another It That Betrays), the ability simply won’t do anything when it resolves.