Razor Rings

The combat clause is the whole design constraint: this only answers a creature that has already committed to an attack or block, which means it does nothing to a threat sitting idle in an untapped stance you never provoke, and nothing against a defensive player who declines to swing. That restriction is what pays for four damage at two mana, a rate that clears most midrange bodies at instant speed inside a combat step whose timing you control. The lifegain rider is the more interesting piece, because it only pays out on overkill: point it at a 2/2 and you bank two life, point it at a 4/4 and you gain nothing. The card rewards you for aiming at the smallest creature that still needs killing, which discourages spending it as premium removal on the biggest thing across the table and encourages it as a mid-race blowout instead. White has a long history of combat-only removal priced below the curve to compensate for the timing hoop, from Reprisal to Divine Verdict, and this sits in that lineage with a burn-style damage number rather than an unconditional destroy, so it reads as red-adjacent removal wearing white's combat restriction. The excess-damage-to-life conversion is what gives it a ceiling in a race: against a board of small blockers it kills and stabilizes in the same click, turning a defensive scramble into a swing in your favor.