Quintorius, Loremaster

Boros graveyard recursion is a strange color pair to hand a spell-recursion engine, because neither red nor white traditionally does much digging in the yard, but this reframes the problem entirely: instead of casting spells from the graveyard directly, it launders them through exile and pays for them with bodies. The end-step trigger converts a spent noncreature, nonland card into a 3/2 Spirit, so every burn spell, artifact, or planeswalker you've already used becomes fuel for a growing token army. Then the activated ability spends those Spirits to recast the exiled cards for free, sending them to the bottom of the library afterward rather than the graveyard whenever they'd otherwise be put there as a spell. That returning clause is the engine's governor: cards don't recur infinitely, they cycle back into your deck, which turns the whole apparatus into a slow-motion value loop rather than a combo that stalls out. The two abilities are deliberately mismatched in speed and scope, and that friction is where the deckbuilding lives: the token generation is passive and inevitable, while the recasting demands mana, a tap, and a Spirit each time, so the ceiling depends on how many high-impact noncreature cards you can afford to feed it. A 3/5 with vigilance is durable enough to attack and hold the fort while the graveyard fills, which matters when the payoff is measured in end steps survived rather than turns spent setting up.