I'm going to put out some thoughts here on the mons of the Fairy leader.
Mega Mawile, probobly with Swords Dance and Sucker punch for OHKOs on most everything.
Gardevoir [possibly Mega] for a general strong special mon.
Klefki for Prankster shenanigans.
Possibly Carbink for hazards?
Azumarill for Talonflame countering and Huge Power Aqua jet.
Togekiss and Clefable for special attacking power. I'd be more likely to go with Clefable, as Togekiss no longer gets STAB on extremespeed, and Clefable gets Moonblast. On the other hand, Togekiss is a great counter for things like garchomp.
Florges and Sylveon for being Bulky. Personally I'd be mor elikely to go with Sylveon, as it has things like Psychock and great HP so it can put a pretty big dent in things. Moonblast can force a switch-out on special attackers too.
My personal thoughts on the final team are: Klefki opener, Gardevoir, Sylveon, Azumarill, Clefable, and Mega Mawile.
Thoughts/opinions?