I would say shoot for a Mega Mawile spread that's bulky enough to take two +2 Dazzling Gleams and a +2 HP Ground attack from Xerneas since it needs to take out Yveltal's main counter ASAP. If you are going to use Yveltal and Mega Mawile, I'm going to give you a link to a useful website I've found for vgc 2016 called battle spot stats. For VGC 2016 information, change Single to Special and make sure the it says "season 14" so it shows an accurate information of the current usage stats on Battle Spot Special.
Mega Mawile stats: http://battlespotstats.com/?game=ORAS&se...ial#Mawile
If you want, try out Modest Primal Kyogre and Trick Room Cresselia with Skill Swap to ensure that you can win the weather war against Primal Groudon as well as mess around with the opponents abilities.
Mega Mawile stats: http://battlespotstats.com/?game=ORAS&se...ial#Mawile
If you want, try out Modest Primal Kyogre and Trick Room Cresselia with Skill Swap to ensure that you can win the weather war against Primal Groudon as well as mess around with the opponents abilities.
