Vespiquen

Pressure
Enemy attacks lose 1 extra PP. Increases wild encounter rate.
Type Tier
Bug / Flying UU
Statistics
Min- Min Max Max+
HP
70
- 281 344 -
Atk
80
176 196 259 284
Def
102
216 240 303 333
SpA
80
176 196 259 284
SpD
102
216 240 303 333
Spe
40
104 116 179 196
Name Item Nature

Tank

Leftovers Impish
Moveset EVs
~ Attack Order
~ Roost
~ Toxic
~ Defend Order
248 HP / 252 Def / 8 Spe

Despite the presence of Heal Order, Roost is preferable, because it temporarily rids Vespiquen of those nasty Ice and Electric weaknesses, and reduces the sting from Rock attacks. Sadly, Vespiquen's low Speed makes even this difficult to take advantage of. Defend Order is mostly a filler, but combined with Roost it could work out.

Name Item Nature

Choice Band

Choice Band Adamant
Moveset EVs
~ Attack Order
~ U-turn
~ Aerial Ace
~ Hidden Power Fighting
248 HP / 252 Atk / 8 Spe

Thanks to Vespiquen's bulky defenses and handful of useful resistances (Ground immune, Grass and Fighting 4x, Bug 2x), it's decently easy to bring in if there's no Stealth Rock up. Hidden Power Fighting seems strange, but it's mostly there for the Rock/Steels in UU.

Other Options

Thief gives you another option against the numerous Pokémon that resist Attack Order. Pursuit can catch a fleeing Hypno or Grumpig off guard if it tries to run away from Attack Order.

EVs

Use the given EVs, but don't forget to make sure that Vespiquen's HP ends up an odd number, letting it survive two switch-ins to Stealth Rock rather than faint on the second switch-in with an even HP.

Opinion

Vespiquen is a really unfortunate case of low Speed meeting bad type and bad movepool. That alone would be enough to kick it down to the limbo of BL, but a 4x weakness to Stealth Rock makes Vespiquen a really hard choice even in UU—make sure to pack a spinner if you plan to use this. The silver lining is that Vespiquen gets some decent stats elsewhere and some very good moves.

Counters

Anything with a strong Rock attack will pretty much always rip into Vespiquen's HP. Vespiquen can't do much of anything to Steel-types; even the ones that don't resist Attack Order. Any offensively-oriented Pokémon that can switch into Attack Order that doesn't mind Toxic will work too.