Valakut, the Molten Pinnacle

A land that wins the game by counting other lands. The threshold is the whole engine: while it taps for red and nothing more, the deck is just waiting on a number, and the moment a Mountain enters while you already control five others, it deals three damage anywhere you point it. Read the wording closely, because it determines how you build. The trigger checks for "Mountain," and this land carries no Mountain type itself, so it neither counts toward the threshold nor pulls its own trigger; the count has to come from six actual Mountain-typed lands before the sixth one starts the burn. That tax pushes the deck toward effects that flood several Mountains onto the battlefield at once rather than generic red duals. Once the count is live, a land drop stops being mana and starts being damage: with five Mountains in play, cracking two fetches for basics is six to a face that had no way to interact. The design is a payoff dressed as terrain. It slips underneath the entire layer of the game built to answer threats, because nobody holds up removal for a land and no counterspell stops a land resolving into play. It reframed what a damage source could look like, hiding a finisher inside the manabase and charging a heavy Mountain-typed commitment in exchange.