Speaking of Mega-Mawile, I've been looking for a way to properly use it in Ubers again for quite some time.
Its great defensive typing, bulk and raw power have always been appealing to me and also allow it to check several top tier threats of the metagame, such as the Latis, Xerneas, Mega Mence without EQ (although Mawile can take one at neutral) or Yveltal. There are two huge thorns in its side though and those are Ho-Oh and the most dominating presence in the metagame, Primal Groudon, which can pretty much switch in for free. The set I came up with solves these issue combined with the right team support:
Mawile @ Mawilite
Ability: Intimidate
EVs: 248 HP / 24 Atk / 236 SpD
Brave Nature
IVs: 0 Spe
- Baton Pass
- Stone Edge/Rock Slide
- Play Rough
- Sucker Punch
EVs in HP and SpDef allow Mawile to avoid the OHKO from +2 Xerneas after Stealth Rock Damage. Stone Edge is supposed to nail Ho-Oh on the switch-in while Baton Pass allows you to take advantage of incoming Primal Groudon, thinking they can switch in for free but then after the BP find themselves in against Primal Kyogre and Desolate Land gone. Primal Kyogre is almost mandatory as a partner for this set because it's by far the best answer to Primal Groudon thanks to getting rid of Desolate Land but I guess passing into something like Groundceus or the Latis is an option as well.
Sucker Punch is a pretty powerful and much needed priority Mawile should always run and Play Rough is the STAB move of choice, taking care of the many Dragon Types in Ubers.
Iron Head and Fire Fang instead of Stone Edge/Rock Slide are also options if you feel like coverage against Steel types and destroying Fairys (and checking GeoXern more reliably) is more important than getting rid of Ho-Oh since there's ofc also the option to just BP on the Ho-Oh switch-in but I just like getting rid of opposing Ho-Oh as soon as possible.
To finish it up, here's a replay for anyone interested in seeing this Mawile in action:
http://replay.pokemonshowdown.com/ubers-208499902
I might have made some bad/risky plays there but it still showcases how this set works fairly well and that MegaMawile can still put in work :]