>>20141572This would be my suggestion.
Get a powersave device, it allows you to copy/restore the data on your X/Y carts. Use it to clone the pokemon you care about. Keep a copy on your cart at all times, and leave a copy on pokebank.
Everything else thats filling your boxes is probably something that isnt gonna hit you too hard if you lose it.
In the meantime, if you have like a handful of pokemon your worried about losing, im willing to make copies of them for you