Responses
Yes and no i guess he didn´t use it on kids so he was not showing us his full serious fighting skills yet...
Well we saw him using it on kids, and tbh he was fighting adults for a while now, idk maybe he will get serious once again in near future, and will fire it once again
Probably yes
Damn after all those chapters I remembered that there was this thing early on in the story, that when he punched someone seriously, it sounded like a gun, plus his name has a gun in it, did author completely forgot about this?