Barricade Breaker

Improvise turns an artifact-heavy board into a fast-cast discount, and this Juggernaut is the payoff waiting for that clutter: a 7/5 whose listed seven mana evaporates the moment you have a few artifacts to tap sideways. That's the trade the design is built around. Big artifact bodies are usually slow because the floor is the full cost; improvise lets the floor drop without changing the printed number, so the same card reads as a late-game brick and an early threat depending on how much affinity-style detritus you've assembled. The catch is the Juggernaut clause it inherits from the creature type's lineage: it attacks each combat if able. That's not flavor decoration; it zeroes out the card's defensive value and turns the 5 toughness into a liability against anything that punishes forced attacks. A body that has to swing into open mana every turn is a different card from one that can hold the ground, and the design wants you to deploy it when you're closing, not stabilizing. The result is a finisher with a built-in clock pointed at both players: it ends games quickly when you're ahead and feeds your opponent's blockers and removal when you're not. The artifact-cost reduction and the compulsion to attack are the two halves of the same idea, a creature priced to crash in and structurally unable to do anything else.