Why can't I put my Rayquaza on the GTS?

So I was playing my friend’s Alpha Sapphire game(I’ve already completed the main game and the Delta Episode), and I wanted to deposit my Rayquaza I got from the Delta Episode holding my Master Ball on the GTS for a Mew(Since the GTS in Gen 6 has mythical Pokemon on it for some reason).

But when I went to deposit it, it said, ‘That’s a special Pokemon! You can’t trade it!’

Now, I know that this message happens when you try to trade a Pokemon with special ribbons on the GTS/Wonder Trades, but I checked and my Rayquaza and it has no ribbons! I also tried to deposit my Kyogre from the story and it said the same thing! But when I tried it with my Deoxys from the end of the Delta Episode, it let me! Rayquaza is a Legendary and Deoxys is a Mythical, so why can I trade Deoxys and not Rayquaza?? I checked and it’snotthe Master Ball that’s doing this; it worked with my Charizard and Heatran.

My game isnotmodified or glitched(at least that’s what my friend told me) and I have not modified it in any way. Can someone please explain why this is happening?

Pleaselog inorregisterto add a comment.

If it knows Dragon ascent it cannot be put on the GTS because it is shared with Pokemon X and Y and dragon Ascent is not a move in X & Y and if the Kyogre has a blue orb which is also not available in X & Y you cannot trade it for the same reason you cannot trade Rayquaza with dragon ascent so take away the blue orb and make it forget Dragon ascent and you should be able to fully Trade It if it still doesn’t let you I’m not sure what’s going on but this is probably what’s going on

The player is not allowed to trade a Pokémon on the GTS if it is holding certain specific items (such as Mega Stones). Unlike in the past, specific event Pokémon cannot be traded at all, regardless of whether it is holding an event ribbon (such as Darkrai caught in Newmoon Island); attempting to do so will yield the message “It’s a special Pokémon. You can’t trade it!”. Attempting to trade a purified Shadow Pokémon with the National Ribbon will also yield this message. Kyurem cannot be traded while fused.

Source

Pokemon That have moves unavailable in X/Y can still be deposited; they just won’t trade with X/Y. That being said, there are 4 reasons that your Pokemon could be untradable:

A: It has the Classic, Premier, or National ribbon.

B: It was glitched/Gamesharked, etc.

C: The recipient Pokemon is from Pokemon X/Y

D: The Pokemon you are trading for is glitched/Gamesharked and was entered into the GTS in a glitchy way, which causesproblems.

Hope I Helped!