Sentinel of Lost Lore
Casting an Adventure creature's spell half banks its second cast in exile: a reservation you have already paid for and mean to redeem later, one the rules never gave anyone a way to cancel. This 3/4 Elf Knight is the first body built to police that reservation on both sides of the table. Its first mode rebuys your own card out of exile, turning a resolved instant or sorcery back into a fresh two-for-one. Its second is the aggressive half: an opponent's Adventure card sitting in exile is a creature they intend to summon, and bottoming it wipes that pending value clean, card-advantage denial that never touches the stack. The third mode is plain graveyard hate, folded in so the trigger is never dead against a board that offers nothing else. Because it chooses one or more, a single entry can redeem your own reservation, strand theirs, and clear a yard in one breath, though most boards will present only one live target. The 3/4 frame matters here: it holds a line while it does its work, rather than folding the moment it lands. It answers a design question the Adventure zone quietly raised the moment it existed. If casting the spell half deposits the creature half for later, someone should be able to cancel the deposit.
