When you hit with both attacks with Double Slice, you flense the target, making it bleed and creating a weak spot.
Archetype
Feat type
Archetype Feat
Level
8
Traits
Archetype
Prerequisites
Dual-Weapon Warrior Dedication
Requirements
Your last action was a Double Slice, and both attacks hit the target.
Actions
1 action
When you hit with both attacks with Double Slice, you flense the target, making it bleed and creating a weak spot. The target takes 1d8 persistent bleed damage per weapon damage die of whichever of the weapons you used that has the most weapon damage dice (maximum 4d8 for a major striking weapon). In addition, until the start of your next turn the target is off-guard, and its resistances to any physical damage types are reduced by 5.
Source: Pathfinder Player Core 2, p. 196
Bring Flensing Slice into a Pathfinder 2e game with The DM Screen.