Manticore

Removal that demands you build the kill before you cast it. The Tail Spikes trigger only fires on a creature an opponent controls that was already dealt damage this turn, which turns this into a two-part play rather than a point-and-shoot spell: you need combat, a ping, or a burn effect to soften a target first, then flash this in to finish it. Flash is what makes the arrangement work, letting you cast it at instant speed once damage has been marked during your opponent's combat and destroy the blocker or attacker that just took it, or ambush a creature that traded partway through a fight. Read as a conditional Murder stapled to a 2/1 flier, the rate looks steep for four mana, and it is: the body is fragile and the removal will not answer a fresh, untouched threat. But the design is honest about what it wants to be, which is combat interaction that pays off a deck already trafficking in incidental damage. It punishes creatures that overextend into a race, and the evasive body still applies pressure even when no legal target for the trigger exists. This one reads worse than it plays when the surrounding cards feed it, and worse than expected when they ignore the damage clause entirely.