Should I keep this Rayquaza?

[wundrweapon]

I don't know what I'd do in your position. I'd probably use it for a "starting gun" as I call them - attack first, and deal as much damage to assist the other 5. For physical attacks going first, your Rayquaza would do you well, allowing other Pokemon to do the rest of the work. And hey, in a double battle, Dragon Dance (along with more effort added on, of course) could be a KO machine

just a thought