Well,someone found a way of how to out smart the game(When i think of it) and can let your perdict what shiny with nature you will egg in an egg.
Its a bit hard to explain,though it dosen't require anything to hack..
Thats the guy who found it out
https://www.smogon.com/forums/showthread.php?t=52180
Some people can't RNG cause they need to find ther game secret ID(I used my AR for that.. ._.)
Though they are still legit in everyway..Heres a little demonstration vid..
https://www.youtube.com/watch?v=8Np5ssscHxE
As for my shinies,i have did a few trades to orbtain them,somtimes i RNG for myself(I love having pokemons with my name 8D) And somtimes i feel like trading them. :P
I used some of them for PBR to check if they are real ._.