Moves
Thanks to Simple, Calm Mind boosts Woobat's Special Attack and Special Defense by two stages each. After a single use of Calm Mind, Stored Power has 100 Base Power, hitting any foe that doesn't resist the move very hard at +2. Heat Wave provides coverage against Steel-types such as Ferroseed and Pawniard, the latter of which is immune to Stored Power. Hidden Power Fighting can also be used in the third slot, as the set would otherwise be completely walled by Houndour. However, Woobat will be forced to lose a point in either Defense, Special Attack, or Speed due to the drop in IVs, making it a subpar option, especially considering Woobat is still heavily threatened by Houndour's Sucker Punch. Roost keeps Woobat healthy as it sets up, preventing it from being easily picked off by a faster Pokemon later in the battle.
Set Details
A Timid nature and maximum investment in Speed assure Woobat hits 17 Speed, outspeeding Pawniard and tying with Mienfoo. The rest is put into Special Attack so that Woobat hits as hard as possible. 76 HP EVs allow Woobat to hit an odd number in HP, reducing the impact of Stealth Rock and slightly improving Woobat's longevity. The 12 EVs in Defense prevent Eviolite Pawniard's Sucker Punch from OHKOing Woobat most of the time. Eviolite improves Woobat's bulk and gives it more setup opportunities.
Usage Tips
Woobat can be used as an early-game wallbreaker or a late-game sweeper depending on your team's matchup. The combination of Simple, Calm Mind, and Stored Power immediately puts heavy pressure on several foes, and is quite useful for punching holes in the opponent's team early-game for that reason. The presence of Sturdy + Berry Juice Pokemon on the opponent's team, such as Dwebble, Tirtouga, and Magnemite, however, can limit Woobat's effectiveness early-game, so Woobat should be preserved for mid- to late-game if these Pokemon are still present.
Ideally, Woobat should try to set up on slower Pokemon that use special attacks, such as Spritzee and Skrelp. This allows Woobat to set up Calm Mind while healing off any damage done with Roost. Woobat can even set up on weaker super effective hits, such as defensive Chinchou's Volt Switch. Keeping Woobat healthy with Roost is important, as it is prone to being picked off by faster Pokemon and priority moves after it gets a KO. Try to avoid Knock Off, too, as Woobat is incredibly easy to revenge kill without Eviolite.
Team Options
Fighting-types such as Mienfoo, Croagunk, and Timburr pair well with Woobat, as they can easily handle the Dark-type Pokemon that give it trouble, such as Pawniard and Houndour, and can also serve as viable switch-ins to Knock Off users in general. Pokemon that appreciate having special walls heavily weakened or defeated, such as Life Orb Abra and Life Orb Gastly, also pair well with Woobat. Memento support from Cottonee or Diglett can help give Woobat extra opportunities to set up Calm Mind. Woobat appreciates having Stealth Rock removed to maximize its setup opportunities, so a Rapid Spin or a Defog user such as Staryu, Drilbur, or Archen can pair well with Woobat to ensure that it stays at full health when it switches in.