Gatekeeper Gargoyle

A six-mana 3/3 flier is, on its face, a non-starter: roughly the body of a two-mana common stapled to a price that asks for a serious reason. The whole design hinges on the counter clause, which converts every Gate you control into a permanent power-and-toughness bonus, paid in full the moment it lands. That makes the Gargoyle a payoff dressed as a creature: nothing exceptional unless you have already committed your manabase to a Gates theme, at which point the floor evaporates and the body scales with the work you have already done. The counter mechanism is the right call over an anthem or a check-on-cast, because it locks the size the instant it enters, so a later land destruction spell or a bounced Gate cannot shrink it back down. Flying is what turns the math into a clock: a board with enough Gates to make this a five-power-or-larger threat also gives it a way over the ground stalls that lands-matter shells tend to build. It belongs to the small family of finishers whose job is to give an otherwise clunky lands-matter archetype a way to close, asking nothing of itself and everything of the board it inherits.