people will only want ut pokemon. so if you are going to raise them to check the ivs. save your game first then raise it to check ivs then turn the power off so the pokemon is back to its low level
if it was flawless youde know because it would most likely be rng.
flawless means its ivs are flawless meaning 31 in every stat. there is a way to check a pokemons ivs by going into serebis main site here is the link.
but it is only accurate once a pokemon is raised to level 20 or higher. so if you had a pokemon lower than that level save your game raise it too 20 and then check it. reseting your game after. hope this helps.