I always do that in Pokemon games, I always carry Pokeballs around and be sure to have a team that helps on that (sleep, paralize and on endgame, false swipe), I insanely love how PokeMMO handles breeding, it is basically a fusion, you are guaranteed to get max IV if you wanted to with enough farming, which is AMAZING!
As for the strong mons, them having a harder level up curve might do the trick, I have to test it out and do some math, I never considered something like that: https://www.reddit.com/r/digimon/comments/1iv3gpt/comment/mehwzut/?utm_source=sh...
I'm pretty sure Shinies are just cosmetics, they do have that single feature while stretching fights but it wasn't that big.
About the endless, so basically a Survival mode? Should it be with your regular team or a side mode starting from scratch ala roguelite?
I was planning on having two difficulty modes, Casual and Normal, for casual you get a sick boost of the good stuff (exp, money, drop rate), you get fully healed when leveling up, recovering at "Pokecenter" is free. (I was thinking on fully healing after a fight, but that is too extreme)
I'm excited about this project, but you got me more hyped about it, thanks! Here are some screenshots with some stuff slapped on top to see what looks better.
