Inferno of the Star Mounts

Here is a Dragon built around a number: twenty. The 6/6 flying, haste body is a fine red finisher on its own, but the firebreathing rider carries a hidden win condition, and it fires whenever the counting lands on the right integer. Push the power to 20 with fourteen activations and the creature spits 20 damage at any target: a player, a planeswalker, a blocker, whatever needs deleting. The design tension is entirely in that arithmetic. Fourteen red mana in a turn is a mountain, so the card asks whether you can assemble a burst of ramp or a doubling effect that folds the requirement down to something a real game can produce, rather than firebreathing your way there one pip at a time. Miss the exact threshold (go from 19 to 21, say, by adding two at once) and the trigger never checks in; the damage only fires when the power "becomes 20 this way," meaning through the ability, meaning through a mana investment you controlled. The uncounterable clause is the quiet promise that the creature resolves in the first place: no permission answers the spell on the way down, though the activated ability and its 20-damage trigger can still be interacted with, and killing the Dragon before you can afford the payoff remains an option. It is a build-around dressed as a beater, a red combo piece that happens to also close games the boring way if the elaborate way never comes together.