Apparently this is fairy's type chart:
SE on:
Fighting; Dark; Dragon
NVE On: Fire, Poison, Steel
Weak to: Poison [ABOUT TIME], Steel
Resists: Fighting, Dark, Bug [Wat]
Immune: Dragon
Some of these weaknesses and resists feel like shoehorns for balance, like the bug resist... if anything I'd say fairy should be weak to bug, since a lot of them seem to be nature spirits and bugs eat plants. A grass resist would have made sense, but Grass doesn't need a nerf, does it GF? And being outright immune to dragon makes no sense as I said when fairy was revealed to be strong against Dragon and is clearly a balance bandage. At least when they added Dark it made the 'Three fears' for Psychic's weaknesses.
I get the Fighting, Dark and Steel relations, however. Surprised it's not weak to fire, but at least it's NVE on it. After all, we don't need more offensive Fire spewed around and Defensive fires tend to suck. [I also guess if it was weak to Fire every Dragon would just FIREBLAST. Hello again, balance bandages!]
Mega Mewtwos are version exclusive. One's Fighting/Psychic.
Mega Garchomp NOOOOO