At the requests of the sparring partners here is my presumptive ruling
In the future i may be better to refrain from a tonne of character development and conversation in a duel as this makes finding the relevant attacks and defenses hard to judge. Or alternatively highlight the attacks. Overall it was a great spar with very much no direct clear winner since there was no attempt to have one by either opponent. Instead both Ban and Kari chose to conduct offensive actions and defenses in a very limited manner.
In a narrow victory, Ban pulls off the win. A united and singular objective, as well as having an effect on his opponent at the end pulls off the narrow victory. Both wrote extremely well and since there are no deaths at the end of this fight I can only say good luck and I look forward to reading where this ends up.