Myr Superion

A 5/6 for two mana is a body that has no business existing at the rate, and the casting restriction is the entire price: you cannot reach into your lands to pay for it, only into mana your creatures make. That single clause reroutes the card out of every fair midrange shell and into the narrow band of decks already producing mana off creatures, the Myr accelerants chief among them. The design tension is elegant: a Myr that demands you have built a board of other Myr (or comparable creature-mana sources) before it will hit the table, which means the payoff arrives precisely when you have committed to the archetype that produces it. It rewards exactly the engine that fuels it and is functionally uncastable outside that engine, a self-limiting constraint that lets the stats run hot without warping the broader game. The lineage here is the old experiment of pricing a creature not in how much mana you pay but in where the mana comes from: the generic cost is trivial, but every pip has to flow from a creature, so the gating is on source, not amount or color. Pay with mana from a land, a Sol Ring, a Signet, and the spell simply cannot be cast, no matter how much sits in your pool. That makes it less a beater you slot in than a capstone you assemble toward, the kind of card whose enormous body is a reward for a deck that earned it.