Jonah Magnus, The Beholding

Exploit (When this creature enters the battlefield, you
may sacrifice a creature.)

Whenever Jonah Magnus exploits a creature, look at
the top three cards of target player's library, exile
one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent
to cast that spell.

"Apologies for the deception, Jon."