Dan is an interesting character, since he gets stronger and more perceptive with every fight, from what I can tell.
At this point in my comic, Josi wouldn't be able to stand a chance.
However, in the 3rd chapter I'm currently writing, she'll learn a very special fighting style from the team Sky Diver's leader and her mentor Shadedancer - who definetly has the greatest fighting experience out of the whole cast - which'll take a long time for her to perfect it (cough the whole saga / 5 parts), spice it up and make it her own, which could benefit her in fighting Dan.
Spoilers
I'm counting any superpowers or legendary weapons out here because - as far as those can go - they will get DBZ-typically insane later on by Origins' 4th part x'D