Well, I don't know if it's possible, but this crossed through my mind after a joke thread involving a fanart made by a pixiv artist named cosmo (hence the name).
The point of this request is to take any of the BW2 games and change the starter Pokemons (Snivy, Tepig and Oshawott) for Lv1 Tangela, Grimer and Magikarp respectively, mainly to use it for nuzlocke challenges.
Here a little screencap I edited in PS:
And the fanart made by cosmo: