(Note: I'm mainly focusing on the SD/Fire Fang/Play Rough/Sucker Punch set, considering this is its considered its best set and that I could already write an essay about how retarded this sole set is. Also, I'm usually assuming a +2 Mawile, considering the counter has to switch in and Mawile can use an astounding array of physical attackers as setup bait)
O-kay, I've been waiting for this for some time and imo this thing simply has to go. This thing has been steamrolling me every single time I faced it, unless my opponent didn't bother to set up fsr. I'm not a very good player, so I thought the more expert players had found more reliable ways to play around this thing, but when I asked in the SQSA thread if somebody knew even a decently reliable counter, the best answer I got was Counter Skarmory of all things >.>
Imo, the combination of retarded power, Intimidate, and strong priority break this thing.
I know raw power is usually a bad argument to ban something, but I think this is an exceptional case. To illustrate my point, I would like to provide two calcs from a situation that happened to me quite some time ago:
-1 252+ Atk Mold Breaker Excadrill Earthquake vs. 124 HP / 0 Def Mega Mawile: 204-242 (75 - 88.9%) -- guaranteed 2HKO (standard spread has about this much HP EVs iirc)
+2 252+ Atk Huge Power Mega Mawile Sucker Punch vs. 4 HP / 0 Def Excadrill: 498-586 (137.5 - 161.8%) -- guaranteed OHKO
Effectively, this means Mawile can use the third strongest Earthquake in OU as setup bait (after Diggersby's and Landorus-T's) in a pinch and proceed to
clean up. (I know this example is generally not advisable, but it works perfectly fine if the opponent's priority users and Sucker Punch resists have been removed). I'd like to stress that we're talking about a 100BP super effective STAB move here coming off 135 base Attack - but if Excadrill KOes an opponent or spins the previous turn, there's literally nothing to stop Mawile from switching in, Intimidating, and proceeding to wreak havoc. Its pre-Mega ability, Intimidate, allows it to set up on virtually any physical attacker after coming in on a free turn.
I also would like to point out some parallels with a blatantly broken threat that has already been banned a long time ago.
reasons for banning Khan: taken from announcement (close)
1)
The raw power of its attacks is too much for the OU tier
<...>
With a virtual base Attack of 213, factoring in Parental Bond, the only Pokémon that can afford to switch into this monster with relative ease are: Cofagrigus, Sableye and a very healthy Gourgeist. Everything else is immediately obliterated by Mega Kanga's attacks. Other gimmick strategies to stop it are Rocky Helmet/Rough Skin (or Iron Barbs) users like bulky Garchomp and Ferrothorn, that use Mega Kanga's ability to hit twice against it;
2)
Mega-Kangaskhan is nearly impossible to revenge kill
Sucker Punch at +2 kills pretty much every wanna-be revenge killer. Pokémon like the Lati twins, the genies, Focus Sash Alakazam and even Genesect (with the X/Y Steel nerf) are all OHKO'd before they can even scratch Mega Kanga. Furthermore, Mega Kanga's 105/100/100 defences are nothing to laugh at, and even when uninvested, they give Mega Kanga excellent survivability. Basically, Mega Kangaskhan's offensive checks are restricted to strong and fast Fighting types such as Terrakion and Mega Lucario;
3)
Mega-Kangaskhan limits team building
Like the 5th Generation Excadrill, Mega-Kanga severely limits team bulding, forcing the player to run dedicated, obscure Pokémon (with the exception of Sableye) to avoid getting swept by it. And, in the case of Rocky Helmet/Rough Skin users, the player is usually just trading their check in order to have Mega-Kangaskhan kill itself through passive damage.
Of course, Khan is more broken than Mawile and comparing these points one on one is guaranteed to bring some logical flaws, but especially the first two points are pretty telling, considering Mawile is simply stronger than Kangaskhan:
+2 252+ Atk Huge Power Mega Mawile Play Rough vs. 252 HP / 252+ Def Slowbro: 373-441 (94.6 - 111.9%) -- guaranteed OHKO after Stealth Rock
+2 252+ Atk Parental Bond Mega Kangaskhan Return vs. 252 HP / 252+ Def Slowbro: 360-424 (91.3 - 107.6%) -- guaranteed OHKO after Stealth Rock
+2 252+ Atk Parental Bond Mega Kangaskhan Sucker Punch vs. 4 HP / 0 Def Latios: 672-792 (222.5 - 262.2%) -- guaranteed OHKO
+2 252+ Atk Huge Power Mega Mawile Sucker Punch vs. 4 HP / 0 Def Latios: 792-932 (262.2 - 308.6%) -- guaranteed OHKO
The unnuanced (the nuance is coming, dw) point I'm making is: if Mega Khan's sheer power against physical walls and revenge killers was reason enough to ban it, there is no reason to keep Mega Mawile - arguing against this would simply be arguing against mathematics. Fortunately, unlike Mega Khan, Mawile doesn't hit twice and is outsped by some walls. Also, Mawile is slightly less bulky than Khan, although this is mitigated by a much better defensive typing and Intimidate. Finally, Mawile is much more reliant on Sucker Punch, although this isn't that bad if a +2 Sucker Punch OHKOes basically anything that doesn't resist it :)
Being a subpar player, I don't want to make any too firm statements regarding the third point, because I'm sure expert players have come up with better ways to cover Mawile than I have. I would, however, like to address some Mawile counters I've heard mentioned.
-Skarmory: If SR is up, Skarmory is OHKOed by +2 Fire Fang. If SR is not up, Skarmory can either phaze Mawile - which doesn't solve anything, Mawile can simply come back later, the only difference being it has no Intimidate to turn basically every physical attacker into setup bait - or Skarmory can survive with Sturdy and Counter Mawile's Fire Fang. While this does defeat Mawile, this would qualify as '
trade one's check in order to have Mega Mawile kill itself' (see point 3 Khan) and it draws uncanny parallels to Haze Unaware Quagsire, in that one is running a completely counterproductive move on a mon that is already starved for moveslots. (Counter works in order to retaliate less powerful physical attacks and then Roost off the damage - when using it to force your own physical wall into a one for one trade, I consider this counterproductive :) )
-Heatran: the standard specially defensive set with Toxic is highly shaky. +2 Sucker Punch does ~80% of damage, whereas Lava Plume has only a small chance to OHKO in return after SR (without SR, an OHKO is impossible). Any offensive set is cleanly OHKOed by Sucker Punch after SR (97% minimum damage). Heatran only reliably beats it if it runs Will-O-Wisp, while it would prefer to run Toxic in order to be more effective on stall and for crippling walls and because it already has Lava Plume in order to spread clutch burns.
-Rotom-W: I've heard this thing is a counter to Mawile, considering it can reliably burn it. While this is true, that's frankly all it can do. If Mawile sets up on the switch, even a burned Play Rough hits physically defensive Rotoms for ~70% damage, bringing it in Sucker Punch's KO range. Therefore, after burning it, Rotom has to switch out and leave the rest of its team to deal with a Mawile that's still just as strong as before setting up; effectively, burning only resets the Swords Dance. Mawile has been crippled in the sense that it can't really switch out anymore, but it still hits like an angry killer bull on steroids. Rotom is as much of a counter to Mawile as Sableye was to Mega Khan; it can burn it, but that's basically it. Iirc, in Khan's case this wasn't considered to be enough.
Afaik, Swords Dance Mega Mawile's reliable counters are limited to a few defensive Fire-types, most notably Arcanine, Heatran, and Bulk Up Talonflame, which is already quite sad to begin with, considering how much defensive Fire-types usually suck. Of these, only Arcanine reliably counters the SubPunch set as well. Heatran is smashed by Focus Punch, and Talonflame can't break the subs and is 2HKOed by Focus Punch.
(Oh yeah: Mawile is a sweeper/cleaner, it's not really prone to being worn down during the match. At least, not as prone as the walls/statusers that are supposed to check it :) )
Personally, I can see no way in which Mawile could be healthy for the OU tier. It has truly obscene power, complemented by strong priority, and can set up on almost every physical attacker in the tier if need be, barring a few really powerful supereffective ones. Don't get me wrong, I know I'm not the best player and I'm always open to better players telling me new ways to counter this thing. However, if the best they can come up with is Counter Skarmory, then that worries me.