>>27969964Arceus gets two Megas. Both make the face light up, and make the ring a neon cream color, as well as make the whole thing glow.
Mega Arceus X has the tips of the rings branch off into arms. It gets a stat-buff to 120, 160, 125, 160, 125, 150. It gets renamed Protean.
Mega Arceus Y has the ring thicken, and the outer part detaches. It's damage animation has the ring moving in front of Arceus to tank the hit. It gets a stat buff like 120, 125, 160, 125, 160, 130. It gets an ability that changes its type to one that resists the next incoming attack, the same type if that one resists it if possible. It doesn't switch to things that are immune to incoming types, but won't change type before being hit by something it is currently immune to.