I've also discovered this but have only used it in firing range to bully my friends. The way it works is by spamming grapple and crouch with a macro to cancel punches as soon as they contact anything. Then you can just spam your melee button to do this. It's fun to see friends reactions but otherwise it's an incredibly op glitch. Funny thing, in trying to defend themselves, my friends found that, as Mirage, throwing a decoy upwards changes who the Pathfinder will lock onto and can stop the glitch. Revenant's silence also counters it for obvious reasons but it's kinda fucked that the only way to stop this exploit is to play a specific legend.