Still want to do the cowgirl idea, but just putting this out to see who's interested.
Basically I was thinking a variation of my Poketitans stories http://www.furaffinity.net/gallery/geno13/folder/198734/PokeTitans but instead of 100' Pokemon chimera girls, I was thinking a small-ish group pertaining to a certain Pokemon type slowly becoming mini-giantess/amazons Pokemon hybrids pertaining to that type.
For example: Imagine Mallow finding a cursed Grazz Z Stone in the jungle and slowly turning half Tsareena with long thick shapely legs, a giant ass, longer vine hair etc. Or even things like TG with male characters.
The only guideline I can think of is that is should involve either Alolan forms of Pokemon, gen 7 Pokemon or Pokemon native to Alola. Also not sure on a story, other than maybe the characters clash/fuck each other and have master over that element from absorbing cursed experimental Z-Stones.