Pokémon Bank restrictions?

[King Robert]

So I'm planning to put all of my "Champion" and "Legendary" Pokémon boxes from Alpha Sapphire into Y, as a temporary holding until I restart the former...and it's not letting me put one of my two Hoopa that I got from McDonald's last November (one's been obtained in Y, which it's had no issues getting into Y, and the other's from Alpha Sapphire, it won't go in) or either the normal and shiny Rayquaza (the former's been caught in AS and the latter's from a Mystery Gift event). What's the deal?

 

[Lufenium]

They may know moves that aren't programmed into X&Y.

If Hoopa knows Hyperspace Fury and Rqyaquaza knows Dragon Ascent, they won't be able to be transferred to Y. You'll have to remove those moves for them to be transferred back.

As such, it's the same with Groudon & Kyogre. If they know their signature moves Precipice Blades & Origin Pulse respectively, they can't be transferred into an X/Y game.