Despite his initial appearance as just another terrible Bug / Flying type, Masquerain is far different from that. With staple Water-type moves such as Scald and Hydro Pump, Intimidate to create switch-in opportunities, and access to Quiver Dance, Masquerain can be a decent Quiver Dance sweeper. While it might seem like Masquerain is outclassed by Butterfree, he has a key move that makes him incredibly unique and worth using: Baton Pass. In RU, the only other Pokemon capable of using the combination of Baton Pass and Quiver Dance is Smeargle, and Smeargle cannot use Quiver Dance to his own advantage in the way Masquerain can, nor is he as bulky as Masquerain. This lets Masquerain act as a powerful offensive sweeper who is also a fantastic team player thanks to his ability to Baton Pass his Quiver Dance boosts to another more dangerous sweeper, allowing it to sweep in his stead. Despite his crippling weakness to Stealth Rock, awful typing, and mediocre stats, Masquerain is a very welcome addition to a team when he is given the correct support.
With Quiver Dance to buff his mediocre Special Attack, Special Defense, and Speed to very respectable levels, Masquerain becomes a very capable sweeper, as he can use his unique coverage in addition to the stat boosts from Quiver Dance to rip through opposing teams. Thanks to Intimidate, Masquerain will have plenty of opportunities to switch in, and even though his typing is filled with crippling weaknesses, his 4x resistances to Grass- and Fighting-type attacks, alongside his immunity to Ground-type attacks, allows him to switch into common threats such as Gallade, Roselia, and Tangrowth, though note that he must still be careful of super effective Hidden Powers from the latter two. However, this is not Masquerain's main niche; what truly separates him from the other generic Quiver Dance sweepers is his access to Baton Pass. Thanks to this gem of a move, Masquerain suddenly transforms from a decent sweeper to a powerful team player with the added benefit of posing an offensive threat.
Bug Buzz and Hydro Pump form Masquerain's offensive coverage, and thanks to their exemplary neutral coverage together, Masquerain can usually deal with most Pokemon quite easily. Bug Buzz is Masquerain's strongest STAB move, and Hydro Pump trashes Pokemon such as Aggron, Steelix, or Entei who might try to switch into Bug Buzz. Furthermore, in RU, the only common Pokemon who resist the combination are Poliwrath and Qwilfish. However, Air Slash is a very decent alternative to Bug Buzz, as only Lanturn resists the combination of Air Slash and Hydro Pump. Air Slash, at the cost of a little power, has the added bonus of hitting troublesome Pokemon such as Hitmonchan for super effective damage. Unfortunately, Air Slash gives Masquerain issues with Pokemon he should have no problem dealing with, such as the omnipresent Slowking, Uxie, and Rotom-C. In the last slot, Baton Pass is naturally recommended, as it allows Masquerain to escape from troublesome situations while passing on the boosts he has accrued to a Pokemon who would easily be able to take on the incoming threat.Team Options & Additional Comments >>>
Even though he has a larger movepool than most other Bug-types, Masquerain is still incredibly limited due to his mediocre stats. Still, he does have a few cool choices at his disposal. Masquerain has a variety of other special moves he can use to hit specific threats, including Ice Beam, Hidden Power Ground, Giga Drain, and Shadow Ball, but most of the time, one of Masquerain's STAB moves alongside Hydro Pump or Scald will provide sufficient coverage. However, because of this excellent collection of special moves, Choice sets are viable options, though Masquerain does not excel at using them. A Choice Specs set is typically too slow and reliant on prediction to do much damage, while a Choice Scarf set is still not fast enough to beat most common threats and is rather weak. The final nail in the coffin for Choice sets on Masquerain is the fact that he is 4x weak to Stealth Rock, which means that he will be unable to switch in frequently enough to KO opponents with his coverage moves.
Masquerain has some neat support options in Stun Spore and Haze, which can be nasty surprises for certain sweepers, but with his slew of weaknesses and average defenses, Masquerain simply can't take on most of these threats. Still, he does have access to reliable recovery in Roost, and Intimidate can help cushion some of those lethal attacks, so it isn't necessarily a terrible option. Masquerain can also set up Rain Dance; his Water-type moves will benefit from the rain, and his resistance to Grass-type attacks and access to Roost are helpful, but other than that, Masquerain has nothing special to distinguish himself from other, more reliable users of the move such as Uxie.
Finally, Masquerain has another boosting move in Agility. While Quiver Dance is usually a much better option due to its Special Attack boost, Agility is viable for a few reasons. First of all, even after a Quiver Dance, Masquerain is fairly slow, and he fails to outspeed threats such as Sceptile, who can then proceed to decimate him with Hidden Power Rock. Agility, on the other hand, will allow Masquerain to outrun these Pokemon and nail them with a decently powered Air Slash, Bug Buzz, or Hydro Pump. Furthermore, it is arguably much easier to find suitable partners who can take advantage of an Agility boost, as almost everything appreciates a +2 boost to Speed. However, the main issue with an Agility set is that Masquerain is simply too weak to be able to sweep, and by using Agility, Masquerain is forgoing his one main niche—passing Quiver Dance boosts—for something that many other Pokemon can do just as well.
Checks and Counters
As a Bug / Flying type, Masquerain's worst enemy is Stealth Rock. Losing 50% of his HP, especially considering he isn't the bulkiest Pokemon around, is detrimental to his success, and by keeping it on the field, Masquerain will be severely crippled. Furthermore, keeping Stealth Rock up limits the number of times Masquerain can Baton Pass his boosts, making him and his team much easier to deal with.
Unfortunately, due to Baton Pass, Masquerain is actually fairly difficult to wall by conventional means, as he can simply Baton Pass out of any counter into a Pokemon who can easily dispose of that counter. Thus, phazers and Pokemon with Haze are probably your best bet in countering Masquerain, as by phazing him or simply removing the boosts, Masquerain cannot simply Baton Pass out. Munchlax and Mandibuzz are the premier choices for the job, as their amazing special bulk will allow them to take on whatever special attacker Masquerain Baton Passes to, and they can phaze Masquerain away with Whirlwind. Similarly, Cryogonal works well, as it also has wonderful special bulk while possessing Haze to remove all the boosts Masquerain has accrued. However, its slew of weaknesses will also mean that it will be easier for Masquerain's teammates to take it down. Other phazers such as Hariyama, Drapion, Steelix, and Slowking are also decent temporary solutions, but the former two's comparatively worse bulk and the fact that the latter two will be decimated by Hydro Pump or Bug Buzz, respectively, mean that you shouldn't rely on them to deal with Masquerain for the entire match.
For more offensive teams, it's important to remember that Masquerain isn't overly fast after a Quiver Dance. As he only outspeeds Pokemon up to maximum Speed base 115s, naturally faster Pokemon such as Aerodactyl, Sceptile, and Accelgor will easily destroy him with a 4x super effective Stone Edge or Hidden Power Rock. Alternatively, faster Choice Scarf Pokemon work just as well, and Manectric, Galvantula, Typhlosion, Scyther, Primeape, Rotom, Moltres, and Rotom-C will all outspeed Masquerain after a Quiver Dance and easily KO him with a super effective move. However, make sure to remember that you can't just haphazardly switch these Pokemon in, as they are almost all hit super effectively by one of Masquerain's STAB moves or Hydro Pump.