>>48932733>they don't even explain how can Rayquaza be the source of MegaevolutionThey didn't because it wasn't the source of Mega Evolution. Rayquaza eats meteorites, which can contain a concentration of Infinity Energy as a byproduct of the weapon.
But even XY already explained this too, in the postgame where touching the Sundial upgrades the Mega Ring-- proving that Mega Evolution isn't because of the Ultimate Weapon but rather it was just the Ultimate Weapon that caused it to be discovered.
Ergo, Mega Evolution exists in every universe completely independent of whether or not the games show it having been discovered.
