Responses
There's no specific scene that shows he knew if ijin can use gun or not. But considering the fact that ijin has saved the SW VIP so many times before, he probably have heard from the seniors that ijin can use the gun well. Probably
Ahh love when he fights so cool! Although, this makes me wonder how his friend will react because I don't think they've seen him be so cruel (break someone's finger).. does the guy with black hair (forgot his name) know Ijin can use a gun even??