The thing is there is little content concerning Pokemon and My Little Pony, and honestly I'm not sure how popular it could be initially, but it could gain a lot of attention due to the high quantity of people who are into it, me included. I'm a bad writer personally but if anyone is up for it that'd be great
There is a My Little Pony story here. However, it hasn't been updated in...four years or so and It doesn't really have a whole lot of content. For pokemon...There's a pretty popular Pokemon Adventure story that's still being updated regularly. I don't know exactly what all content the story entails as I have not read through it in its entirety and I don't know if you're looking for Trainers fucking Trainers, Trainers fucking Pokemon, or Pokemon fucking Pokemon. The latter two, I would suspect you wouldn't find a whole lot of on Chyoa as it skirts dangerously close to the site's bestiality rules. Yes, I know that many Pokemon have at least human intelligence, if not greater. Some could even pass The Harkness Test which is the general test that writers on this site use to determine whether something is bestiality or not. Still, you would be hard pressed to find a writer on here willing to attempt writing a story involving entirely Pokemon on Pokemon or Pokemon on trainers without at least asking permission from a site admin first.
There's also a non-erotic https://chyoa.com/story/Pokemon.613 out there that could be adopted and taken over.
I have also encountered an MLP story here: https://chyoa.com/story/Ponyville-After-Dark-(Contributors-Welcome!).75114
