>>15869512Like previously said, a .pkm file is only 136 bits, and it contains only enough info to tell the game what pokemon it is, gender, the pokemon's trainer ID number, the secret ID number, what ball it's in, what item its holding, moves, ev spread, IVs, in what game it was encountered, on what route, it's level when encountered, and it's current amount of exp.
All of this information is editable in pokegen.
When you use pokegen on an emulator rom or SD card, you are changing the save file so that a particular pokemon appears in a slot in your pc, as if it was always there. There is no extra information in a .pkm file that could be used as a red flag or marker to see if it was just proofed into existence. Only illegal or impossible pokemon could be accurately filtered, say it has moves it could never learn, or max ev's in every stat.
People generally make legal mons though, since they're usually meant to be used competitively.
Hackmons will be converted to the new file type and enter pokebank just like any other pokemon, because they are identical