I was never particularly into the fighting, so I'm not sure if that's my advice or if that disqualifies me from offering advice in the first place. :P Not exactly because I felt bad for the cute things (though I definitely did), but even with all their cool, dangerous powers there just tended to be lots more interesting stuff to do with those powers when it wasn't just gladiator matches. A simplistic fix for this is to keep the training of pokemon for everything from public service to agriculture to warfare that shows up in various pokemon media, but back off on the sheer density of arena battles in the setting. But if you can really sell the story of cute monster MMA fighting separately from "like pokemon, but," that could work too. For me at least, it's a tough sell. I want to be friends with the squirrel turtle and go on adventures.