Wolfox

Yes, Protean Greninja exists. That doesn't mean it's any less broken or any less disgusting, or negate the fact that it had to  be banned in the generation it was introduced in. If SuMo OU was not chock-full of things that are equally broken and centralising, it'd still be banned. If you'd want to make more broken things, be my guest; just bear in mind the consequences.

Many fangames or ideas get carried away and make everything overpowered or awesome. Syndrome logic doesn't work very well with Pokemon, as evidenced by the generally overcentralised nature of SuMo OU. Pokemon is more fun if everything is more or less balanced, not if it is dominated by a very small number of very strong Pokemon, even within the same tier.

I agree there. I play monotype myself, and there it's not fully based on some mons... unless you play fairy, cuz most mons on a fairy team are the fairy team...

@Ironbound Yeah, that's what I was getting at. It's extremely and obviously OP and yet it exists, because evidently somebody on the dev team didn't think it through. Or just didn't care.