Oh, of course, guns in a martial tournament... Sure... And they think that after doing something like that, they'll get to keep the money? If this had even a sliver of realism in it, the whole world would turn against the family using a gun in that situation (regardless of whether or not the gun can help them win whatever bet they have made) and they'd disappear from the face of the planet. Of course, since this is a sad excuse of a cultivation story, no such thing will happen because "logic"