I think you mean Persona 3. ^_^
And yeah, this could end badly. The crossover would work up to a point, but I have a hard time seeing Kyon fighting at all. He's much more laid back. And going by the Persona users we've seen, the fact that he doesn't have any drive to change himself means that he lacks the potential to use a Persona. I can explain more if you're curious, but it's off-topic for Haruhi.
And yeah, this could end badly. The crossover would work up to a point, but I have a hard time seeing Kyon fighting at all. He's much more laid back. And going by the Persona users we've seen, the fact that he doesn't have any drive to change himself means that he lacks the potential to use a Persona. I can explain more if you're curious, but it's off-topic for Haruhi.