I cannot echo this enough. Just to emphasise the current worthlessness of Piercing Talon. It takes four uses for it to beat Full Thrust. This isn't including the loss you'll suffer for dropping Fang and Claw. Put simply, Piercing Talon may as well be deleted if they aren't going to both buff it and use it without breaking your combo. 300 potency would be a perfect compromise so it's still not pulling ahead of your actual combo but makes disengagement not nearly as punishing.