There’s so much obscure tech in the venerated Guilty Gear XX Accent Core +R, it’s no surprise there are still videos coming out about it. Though this trick probably has been known and used by the most arcane masters of +R, it’s nonetheless well-presented in the video below.
Clayton chapman explains an “advanced proximity blocking” trick: whenever characters in Guilty Gear get ready to block, they switch their stance. Certain characters (not everyone!) have more than one blocking stance, which means that their hurtbox slightly alters. Clayton shows this below mostly with Ky and Potemkin. Ky uses Stun Raising to show that some attacks would trigger a taller box on Potemkin. In effect, you could force Potemkin to block attacks at certain spaces.
Read the full YouTube description for an explanation from the player, who talks about another setup.
Source: Clayton chapman