Dreadhorde Arcanist
Snapcaster Mage cast a spell once, from your hand, at instant speed. This does the recursion instead: it turns the graveyard into a repeatable spell source, but pays for that engine with a hard ceiling. The recastable spell's mana value must be less than or equal to power, and the printed power is 1, so out of the box it loops one-mana instants and sorceries and nothing bigger. That single number is the entire balancing act. Every point of power you add (an anthem, a pump spell, equipment) widens the window to two, then three, then the whole graveyard, so the card's payoff scales directly off a stat that red is happy to pump. The exile clause is the throttle on the loop: any spell it fires that would return to the yard leaves the game instead, so you cannot just recur the same free spell into itself and win on the spot. What makes the effect feel dangerous is timing. The trigger is on attack, before blocks, so you cast the recurred spell inside the combat step: a removal spell to clear a blocker, a burn spell to the face, a ritual to power out something else. It rewrote the value ceiling on cheap red spell decks by converting each attack into a graveyard recast, and it did so on a two-mana body durable enough to keep coming back for more.
