Flowstone Salamander

A creature that punishes its own blockers, with a repeatable mana sink to do it. Most combat-damage abilities care about who a creature attacks or what it deals damage to broadly; this one narrows to a single, very specific window. The ability only targets a creature already blocking it, which means the value lives entirely inside the combat step. Hold up enough red mana and an attacking Salamander becomes a one-creature wrecking crew: a 3/4 body that can ping a chump-blocker to death before combat damage resolves, or whittle a larger blocker down so that when damage is dealt it dies for free while the Salamander survives. The constraint is the whole design. It cannot reach out and snipe arbitrary creatures, cannot soften a board on defense, and cannot do anything outside the moment a defender commits to the block. That makes it a pressure tool rather than a removal engine: the threat of the activation taxes how an opponent blocks more than it actually clears the way, since a blocked attacker with no trample still deals no damage to the defending player no matter how dead the blocker is. Tempest leaned hard on this flowstone design language, a clutch of creatures whose stats or abilities you paid red mana to push, and the Salamander is the combat-step expression of that idea: a finisher whose ceiling scales with how much red you can dump into a single attack.