Masquerain

Intimidate
Lowers the foe's Attack 1 stage. Decreases wild encounter rate.
Type Tier
Bug / Flying UU
Statistics
Min- Min Max Max+
HP
70
- 281 344 -
Atk
60
140 156 219 240
Def
62
144 160 223 245
SpA
80
176 196 259 284
SpD
82
180 200 263 289
Spe
60
140 156 219 240
Name Item Nature

Choice Specs

Choice Specs Timid
Moveset EVs
~ Bug Buzz
~ Ice Beam
~ Hydro Pump
~ Air Slash / Shadow Ball / Energy Ball
4 Def / 252 SpA / 252 Spe

Mediocre Special Attack and poor Speed aren't helping Masquerain, but it does have a good movepool for this. Shadow Ball is mostly for Rotom, although a Hydro Pump will do some decent damage. Energy Ball isn't required, but it does OHKO Whiscash and stops Lanturn walling you.

Name Item Nature

Stun Spore

Leftovers / Life Orb Modest
Moveset EVs
~ Stun Spore
~ Air Slash
~ Hydro Pump
~ Shadow Ball / Bug Buzz / Ice Beam
248 HP / 252 SpA / 8 SpD

Stun Spore what you can and try to get some luck with the flinch rate of Air Slash. The rest of the set is for type coverage.

Name Item Nature

Baton Pass

Leftovers / Petaya Berry Modest
Moveset EVs
~ Agility
~ Baton Pass
~ Hydro Pump / Substitute
~ Air Slash / Bug Buzz
40 HP / 252 SpA / 216 Spe

Get your Speed up with Agility and pass it to a more threatening sweeper. Substitute is also available for passing, but you'll lose some type coverage if you use it. However, you can use Substitute to get down to a berry boost. EVs provided allow Masquerain to out run max Speed Electrode after an Agility.

Other Options

Silver Wind can go on the Baton Pass set if you're feeling lucky enough to grab a stat boost to pass on.

EVs

Always max Special Attack. See each set for specific EV spreads. Remember to always make Masquerain's HP an odd number. This lets it survive two switch-ins with Stealth Rock rather than faint on the second switch-in.

Opinion

Earthquake immunity, 4x Fighting resist, and Intimidate do give Masquerain a few opportunities to switch in. The problem is it doesn't do much once it's there. Stun Spore can be helpful and unlike most of his fellow Flying bugs, it can actually do plenty of damage to the Rock/Steel-types with Hydro Pump and hit Flying-types with Ice Beam.

Counters

Steel-types do OK since they resist both STAB attacks, just watch out for Hydro Pump, especially with Rock/Steel-types like Bastiodon. Same goes for Magcargo and Flareon, just avoid Hydro Pump and they should KO Masquerain without much trouble.