>>21902047252+ Atk Rayquaza Brave Bird vs. 0 HP / 0 Def Mega Mawile: 114-134 (47.3 - 55.6%) -- 75% chance to 2HKO
+1 252+ Atk Rayquaza Brave Bird vs. 0 HP / 0 Def Mega Mawile: 170-201 (70.5 - 83.4%) -- guaranteed 2HKO
Brave Bird used because Showdown's calc doesn't have Dragon Ascent yet. I've also upped Ray's base offenses to 180, to match its mega's. But then again, Ray can get V-Create, so if you use the fourth moveslot for that instead of Meteor or whatever other coverage you'd get this at worst.
0 Atk Rayquaza V-create vs. 252 HP / 252+ Def Mega Mawile: 268-316 (88.1 - 103.9%) -- 25% chance to OHKO
Unless your opponent has the mawile at maxed physical bulk, and you, for some inexplicable reason, decided Ray needs no boosts, no EVs, and a neutral nature, that mawile will just barely tank a single hit, if it's lucky.
