I'm just testing and it's not that easy to understand.
well bulbapedia helped me to make a legit-like special trait, serebii has per pokémon data but for the previous game...
anyway I wanted to change one arceus (who was something like 2300 in power), I turned it into a Pikachu and it... it's 1433. I suppose the power is totally related to the species.
I also made a spiritomb from another pokémon above 2000 and it ended up being 1685.
...I think I'll stick to letting Pokémon being their own species, but the king's challenges are very tough, I still have a low level one where I got to not destroy any tower, but I still didn't beat 300 pokémon... so even with cheats, this game is tough.
people are mentionning how it'd be nice to be able to change the power, I'd like at least to be able to see it, so it helps me know which Pokémon I'm viewing. also it could be nice to change the value of pokémon's use, which affects return and frustration.
last thing, is it actually possible to read the dat files in the save folder? all i see is a bunch of garbage characters, I suppose the software I'm using doesn't have the right language...