I don't quite get how to beat Roxanne since I have the counter types of her pokemon and still she outdmgs and outtanks every attack of mine. Can someone explain what i could be doing wrong or how they beat her? TwT

this game is tough, and requires you to know about EVs and IVs at minimum.

Take some time to map out her movesets, set up the moves and EVs you want using the mochi guy in the market and the held item guy.

Formulate a plan for every pokemon you're up against. Treat it like an actual boss fight and not a pokemon fight. I forget if you can possess during boss fights but if you can, you get an instawin if you get them down to 1. Also, normally consumable items arent here, so you can cheese at least 1 mon with FEAR (focus sash, endeavor, quick attack, rat (or any other mon with endeavor+priority))

I used sandslash with rapid spin for that first Pokémon that sets up spikes (wiped it, because the ai tells them to set up spikes before anything else, and getting rid of the spikes repeatedly traps them in that loop) and got lucky that the second one I could also use sandslash for. The point is, Trial and error different Pokémon against Pokémon of theirs, and eventually you'll make it.