That perverted pokemon adventure story that I think of frequently but can’t claim to be actively working on has this system for predation and vore to make it non-fatal and I just want to talk about it because i just love how I did it and what inspired it.
Basically, pokemans can eat most mons smaller than them naturally, and full-tour through intestines less complex than anything we have. As most pokemon with mouths have anuses, thoroughly ‘digested’ pokemon are evacuated through it, usually delirious, missing levels, and covered in a thin film of white sap, a physiological form of experience.
The white sap is extracted from ingested pokemon when touching stomach fluid, resulting in nutrients, XP and energy stealing that is the main point of pokemon predation. Preyed upon mons can devolve in this way, and going past basic form can reduce them to nothing. Very scary, but rarely a problem, as most hunters are rarely desperate enough to prey on the paltry xp of a level 1. Bug types however, fear this fate the most.
Now what helped me make this silly-ness was an old, non-pornographic fan-comic with a gardevoir. She was an office woman getting on in years and met some shady mons that offered her a treatment to make her feel young again. This seems to work and she goes back for more sessions before she discovers her powers are getting weaker and she begins to feel her age again. Going back to complain the shady mon reveals his ruse that he had been utilizing gulpin(the stomach pokemon, if you recall) to extract a white goo from her body that would be processed into rare candies. Without wishing to spoil, she’s perfectly fine by the end, even if temporarily reduced all the way to a ralts.
I thought the concept was brilliant and adapted it into the story element above.