Genestealer Locus

The named ability fires whenever a creature attacks a player, and the direction it bends combat is the whole design. When a creature attacks you, it hands that attacker -1/-0; when a creature attacks one of your opponents, it hands that attacker +0/+1. The second clause is the strange one: a defensive body that materially rewards everyone else for swinging away from you, feeding toughness to armies you will never have to block. This is pillow-fort work built on redirection rather than fog effects, nudging aggression toward the player beside you while quietly taxing anyone who comes at you instead. The -1/-0 rarely turns off an attack by itself, but stacked across a crack-back it blunts alpha strikes and can flip trades in your favor at zero card cost. The +0/+1 is the diplomacy engine: it makes you the least appealing target not by threatening punishment but by improving every other line of attack on the board. Because the triggers resolve automatically whenever a creature attacks a player, the card governs politics through combat math whether or not the table is watching for it. The 3/3 frame is incidental to the effect; the value lives in a board where creatures swing every turn, and every one of those attacks passes through this filter first.