Why won't my Rayquaza mega evolve?

Question

I have Alpha Sapphire and my Rayquaza is level 82. I caught it from the Sky Pillar during the Delta Episode. It could mega evolve before, but now it can’t. I don’t know if this will help, but its moves are Fly, Outrage, Rock Smash, and Surf. It is holding a Soothe Bell.

Comments

Thank you guys for the help, I didn’t know he had to have a specific move to mega evolve.

Answer 1

The player can Mega Evolve any Rayquaza that knows Dragon Ascent.

In order to Mega Evolve, Rayquaza has to know Dragon Ascent. Zinnia's grandmother, who is in Meteor Falls, will teach it to your Rayquaza.

Source

Answer 2

The only way to Mega Evolve Rayquaza is by teaching it Dragon Ascent, if it does not know Dragon Ascent, then it will not Mega Evolve. If you wanted, you could give it an item since it doesn't need a Mega Stone and it will still Mega Evolve. You could give it, a Focus Sash, Life Orb, and stuff like that.