goddamnit, living under a rock?
it was found out, that the shiny locked pokemons ylvetal ,xerneas and zygarde all is unobtainable unless you hack.
which in short means, you cannot gts them, you cannot trade them with an person nor yourself on another 3DS.
which in even more short means.
hack the ylvetal, otherwise you won't get it.
it is confirmed.