Tail Slash

Fight effects live in green's wheelhouse, where the trade is symmetrical: both creatures swing, and your attacker eats damage back. This version cuts that symmetry out entirely. Your creature deals its power to theirs and takes nothing in return, which turns the spell from a brawl into a clean execution. The cost of that one-sidedness is the constraint every fight-style removal carries: something already has to be in play to point the spell at, and its power has to be high enough to finish the job, so the effect is dead on an empty board and embarrassing when your only body is a one-power dork. What red gets out of borrowing the mechanic is removal that scales with the board it already wants to build: a big attacker doubles as a removal spell, and at instant speed it can ambush a blocker mid-combat or pick off a creature on the opponent's turn. It is red doing in its own idiom what green does with Prey Upon, minus the risk to the creature you are spending mana to leverage. The catch is that red rarely fields the kind of oversized bodies that make power-based removal reliably lethal, which keeps the effect honest: it rewards a board you have already committed to rather than functioning as standalone interaction.