Conquering the trading system (X/Y) - Page 2
Well my dreams of trading over 100 Deoxys over the GTS is over :(.
You can still Wonder Trade them. Though you'll receive crapmom 80% of the time. But if it's just for spreading it works. :P
EDIT: actually I doubt they'll make it past PokéTransporter hack check in first place. Despite it being infamous for being awfully bad, a hatched Jirachi/Deoxys are kind of an exaggeration. :P (not even Shiny WISHMKR Jirachi makes through, even though it's legit, but Hall of Origin Arceus does, or at least did back in 1.0).
Sanquii did find a way to make Pokémon have a "fateful encounter", but you'd need a glitch move as you need a move with 128+ base pp to convert the Pokemon into a "fateful encounter".
I don't think the PokeBank filter really checks for "Undiscovered Pokemon hatched from an egg", but, you never know.