Hello, I was digging in the rom data of Pokemon ORAS and i found some Pokemon that haven't been used in the final game.
These pokemon are:
Mega Flygon, Has higher special attack.
Mega Spinda, It still looks like Spinda but Bigger and Buffier
Mega Dragonite, This one looks like it wasn't finished because it has not changed.
I have made a video that explains this and more. :
https://www.youtube.com/watch?v=cYucKL6V1Uc