[ No! Nothing like that! ]

I haven't battled a Gym Leader, myself, but, the battles I've been in haven't been violent at all. [ Though... to be honest, all he's battled have been a little girl who was pretty set on nobody getting hurt, and a bunch of wild Pokemon... ] You 'win' by knocking out the other opponent's Pokemon~!

[ So there's no death and shouldn't be any blood or anything. If there is... you're doing it horribly wrong. ]