I'm building a duelist that has Punishing Kick and a rapier as her main weapon. Now do I just add the Punishing Kick to my normal attacks, or do I need to make an unarmed strike in order to use it?
The rules don't appear to state that you need to make an unarmed attack to have it work, but I could be wrong.
The feat does not explicitly say it has to be an unarmed strike, but I strongly suspect that the intention is that it be only usable on unarmed attacks. Alas, other abilities have weird sounding names, considering how you can combine and use them.