Given how it'll be coming to OU in about a week or so - I think it'll be a good time to review
Mega Mawile, and why I think it'll be staying in OU:
Mawile-Mega @ Mawilite
Ability: Intimidate
EVs: 240 HP / 252 Atk / 16 SpD
Adamant Nature
- Iron Head
- Play Rough
- Sucker Punch
- Swords Dance
I presume this was the B&B set back in XY? Something like this, anyway.
Without further ado, here are the reason I think that Mega Mawile will be a not-quite-top-tier but welcome addition to OU in S&M:
1) The Sucker Punch nerf, and Tapu Lele:
Back in XY, I heard that SP was mostly what pushed Mega Mawile over the edge (as well as it's 210 Attack through Huge Power), for some of the things it could kill without challenge after a +2 boost:
(XY):
- +2 252+ Atk Huge Power Mawile-Mega Sucker Punch vs. 0 HP / 4 Def Garchomp: 342-403 (95.7 - 112.8%) -- guaranteed OHKO after Stealth Rock
- +2 252+ Atk Huge Power Mawile-Mega Sucker Punch vs. 4 HP / 0 Def Greninja: 228-269 (79.7 - 94%) -- 43.8% chance to OHKO after Stealth Rock
- +2 252+ Atk Huge Power Mawile-Mega Sucker Punch vs. 168 HP / 0 Def Magnezone: 292-344 (90.4 - 106.5%) -- 75% chance to OHKO after Stealth Rock
However - I feel as though these things this gen will be less of the case, not just because of the BP nerf (80>70), but after the universal nerf to priority this generation, see Queenly Magesty/Dazzling; Psychic Terrain; the death of Bird Spam after the nerf to Gale Wings; and (as I said) Tapu Lele (Psychic Surge). Firstly, some new calcs:
(S&M):
- +2 252+ Atk Huge Power Mawile-Mega Sucker Punch vs. 0 HP / 4 Def Garchomp: 300-353 (84 - 98.8%) -- 37.5% chance to OHKO after Stealth Rock
- +2 252+ Atk Huge Power Mawile-Mega Sucker Punch vs. 0 HP / 4 Def Greninja: 198-234 (69.4 - 82.1%) -- guaranteed 2HKO after Stealth Rock
- +2 252+ Atk Huge Power Mawile-Mega Sucker Punch vs. 128 HP / 0 Def Magnezone: 255-301 (81.4 - 96.1%) -- 18.8% chance to OHKO after Stealth Rock
That's still a lot of damage - I'm not denying it. However, keep in mind two things: A) the drops in % chance to OHKO, and B) this was all after a +2, meaning that without it, Mega Mawile get's fairly easily countered by good Steels like Heatran and Ferrothorn (the latter may get sniped by the off Fire Fang, but by then you know that it gets walled by most Fire types) - alongside being forced out of it's +2 Attack and losing momentum. This goes without mentioning how slow MM is, and without it's priority gets whittled down a little too easily to be considered unhealthy for the tier, alongside getting chuncked off by plenty of good Ground Types such as Landorus-T; Diggersby and Garchomp (and I know Ice Punch is a thing, but a backup Steel doesn't sound like a symptom of Meta centralization to me tbh if the case were to arise).
And even THESE calcs end up down the drain when we bring Tapu Lele into the fray - a mon whose presence denies priority (as if it's MU with Mega Scizor wasn't enough indication), leading to Mega Mawiles' central flaws to stick out - mainly it's Speed that I touched on earlier, and it's mehish Sp.Def and HP. No, i'm not saying Lele can beat MM 1v1, but I do think Psychic Terrain can find support in key situations, and worsening Megawiles matchups under it. I don't think I really need to go too deep into this... however...
2) Z-moves, the 'shieldstun patch' change to Megas (to those that play Sm4sh, I think you'll get why I called it that) and Mega Mawile's place in the power creep:
Power creeps are a general phenomena that each metagame goes through. And with MM being sin binned for the whole of ORAS (the generation that bought us Mega Metagross; Mega Slowbro; Mega Sableye and others); as well as being forced to sit out the first 4 months of S&M, I would say that Mega Mawile's 210 Attack and other things related to it, while still jarring, is far more in line with what we consider sensible in today's metagame (it's one of the reasons I thought Lunala could be unbanned at some point, but we don't speak of that here...). Options such as Xurkitree with it's 173 base Sp.Atk, and LO Kartana (which equates to... what, 240+ attack?) are two extremely powerful, yet nowhere NEAR top tier examples I can think of off the top of my head that can justify Mega Mawile's place here. Hell, Beast Boost could almost do the talking for me... but I digress.
With it's status as Mega Evolution, Mega Mawile is also unable to make use of the Z-moves present in S&M - another symptom of the power creep in Sun & Moon. What's that? Mega Mawile could punch holes in things? Well so can things like Hoopa-U, Manaphy and Grachomp with Z-crystals corresponding their STAB! Not to mention things like 'MagDoom' Grassium Z Heatran and the utility certain Z-status can bring about (*ahem* Z-Conversion Prygon-Z *ahem*). The universal change to Mega Evolution's has also kind of left Mega Mawile in the dust, as while it did not get touched from said change - the fact that other Megas such as Mega Beedrill (also coming in the same week); Mega Metagross; Mega Pinsir and Mega Alakazam got sweeping buffs brings Mega Mawile down in the grand scheme of things. Considering Megawile will likely have competition from the following, and others, on a team for this spot - that's saying a LOT.
Conclusion:
I'm not trying to say 'Mega Mawile sucks, do not use' when making this post... but I am trying to say that it isn't quite the overwhelming monster it was back in XY, and I believe it is far more welcome in S&M's metagame after making the comparison. The effects it will have on teams will not be half as unbearable, and I think it will definitely spice things up a bit.
Welcome back, Mega Mawile - I think we've all missed you!