Promise of Loyalty

Symmetry is the trick that lets a mass-sacrifice effect resolve without a table revolt. Instead of a one-sided wrath that crowns the caster as archenemy, this forces every player, the caster included, to keep exactly one creature and sacrifice everything else. That structural fairness is what makes it politically survivable: nobody was singled out, so nobody has grounds to gang up in retaliation. The vow counter is where the design earns its second life. The creatures that survive are not merely alive; they are bound not to attack you or your planeswalkers for as long as the counter stays put. So you clear the board down to one apiece and then sit behind a ring of survivors legally forbidden from swinging your way. Every opponent keeps a single creature that can still point elsewhere; you keep a single creature plus a promise that theirs stay off your throat. The base case is already lopsided in the caster's favor while looking scrupulously even-handed. The catch is that the protection is only as durable as the counter: the restriction lasts exactly as long as a creature has a vow on it, so stripping that counter (yours or an opponent's, by removal or by any effect that shifts counters around) frees the creature to attack you again. This is a pillowfort wrath as much as a board sweep, clearing the field and, in the same motion, buying the caster a peace the destruction alone never would.