From Pathfinder Lost Omens Tian Xia Character Guide, which isn't enabled.

Shadowplay

FEAT 5

Activity 1 action

Requirements Your last action was a melee Strike that damaged your opponent.

As your blow lands, you detach from your shadow to get the drop on your enemy. You attempt to Tumble Through the opponent's space, with a +2 circumstance bonus to the Acrobatics check. If you succeed, your shadow rises up from the ground, flanking your opponent until the beginning of your next turn.

Pathfinder Lost Omens Tian Xia Character GuideORC