White Dragon

Six mana buys a 4/4 flier that pins one opposing creature down for a full turn cycle, and that arithmetic is the entire design brief. The Cold Breath trigger is a soft Icy Manipulator stapled to a body: tapping an opposing creature and locking it through the following turn is not removal, but it clears the ground long enough for the flier to start connecting, or peels away the one blocker standing between you and lethal. The effect is deliberately front-loaded onto the enter trigger, so it fires once and rewards being flickered or rebought rather than left on the battlefield to grind. That single-shot tempo swing is the payment for a creature otherwise unremarkable at the cost: no evasion beyond flying, no recurring value, a body that trades down against most six-drops. The interesting seam is timing. Tapping a creature does nothing about a spell already on the stack, and it leaves an untapped attacker free on your opponent's turn if they held one back, so this plays as a proactive tempo card, not a defensive one. It wants to come down when you are ahead and turn a stalled board into an open lane, the plodding heir to the blue tap effects that used to gate combat for a single mana.