[ORAS & XY] Pokemon legitimacy thread

[Lested]

Ok so I am asking out of curiosity, if I make a pokemon with PKHeX and make it under all the "legal" terms so much that it looks like a legit, for an example a Suicune and then I take it to a regional or some official event. Is there a way they will now if a made pokemon? Do they have a special way of checking them (like a machine)? Or is it ok if I can trade, play on battle spot and do the pokebank transfer? is it the same "check" like the battle spot? I know too much questions sorry, but I haven't seen a discussion about this anywhere else.

BTW sorry for my bad grammar, English is not my native language.