Sunflare Shaman

The whole conceit hangs on a self-inflicted wound that scales with the same number it deals out. Each Elemental in your graveyard makes the activation hit harder, but it hits the Shaman just as hard, and with only one toughness the floor is brutal: the first activation that does any real damage at all kills the creature outright. That makes this a build-around with a single honest use, fire it once for everything you have. The reward sits in the deck around it: cards like Smokebraider that feed the tribe, Elementals that die into the yard, anything that turns a one-shot detonation into a payoff worth a card. The repeatable-tap framing on the ability is a kind of cruel joke, since the math that makes a second activation tempting is exactly the math that prevents one. It belongs to the lineage of self-damaging artillery that asks you to time the burn rather than rely on it, but where most such cards bleed you out slowly, this one bleeds itself out instantly. The one mercy in the design is the timing: with no restriction printed on it, the ability fires at instant speed, so the detonation can wait for a creature stepping into combat or an end-step face shot. The whole thing is a wager on graveyard density: the more committed your Elemental engine, the closer this gets to a flexible Bolt for the price of a body you were going to spend anyway.