Bulky Support (Vullaby) (F) @ Eviolite  
Ability: Overcoat  
Level: 5  
EVs: 36 HP / 76 Atk / 156 Def / 236 SpD  
Adamant Nature  
- Knock Off  
- Brave Bird  
- Tailwind  
- Roost / Protect
Set Details: Knock Off is a staple of Little Cup, removing opposing Pokemon's items like Eviolite, while allowing Vullaby to hit decently hard. Brave Bird is Vullaby's main STAB, and threatens common Pokemon such as Mienfoo and Foongus. Tailwind helps Vullaby's whole team be more threatening with their speed doubled for three turns. Finally, Roost gives Vullaby more longevity, so that it can set Tailwind more times during a match. Alternatively, Protect is also an option, since Vullaby is a common recipient for double targeting due to its low speed and it usually not having a moveslot for the move.
This set's EVs are set to give Vullaby as much bulk as possible, further bolstered by Eviolite, while also giving it some Attack investment so that it can still hit reasonably hard. Overcoat allows Vullaby to be a reliable switch-in to Spore, as well as being immune to Rage Powder redirection from Foongus.
Vullaby is a versatile enough Pokemon to fit many teams, as most Pokemon with middling to good speed can benefit from Tailwind. Wallbreakers like Gastly and Mudbray appreciate Tailwind support a lot, as well as Vullaby removing opposing Pokemon's Eviolites. Foongus can also fire off fast Spores with Tailwind support, and both it and Pawniard can help deal with Spritzee and Trick Room in general for Vullaby. Vullaby is most threatened by Onix and Electric types, so Pokemon that can deal with those, such as own Onix, Chinchou, and Mudbray, make good partners. The aforementioned 3 also greatly appreciate Tailwind allowing them to outspeed Ponyta, which would otherwise threaten them with either Will-o-Wisp or High Horsepower.

Nasty Plot (Vullaby) (F) @ Eviolite  
Ability: Weak Armor  
Level: 5  
EVs: 116 HP / 240 SpA / 116 Spe  
Modest Nature  
- Nasty Plot  
- Dark Pulse  
- Air Slash / Heat Wave  
- Protect  
Set Details: Nasty Plot allows Vullaby to double its Special Attack, and coupled with a Weak Armor speed boost, allows it to function as a potent setup sweeper. Dark Pulse is Vullaby's main STAB, hitting a lot of the metagame for at least neutral damage while also having a nifty flinch chance. Air Slash covers all Pokemon resistant to Dark Pulse except for Pawniard, hits the common Fighting types and Grass types for super-effective damage, and also has its own flinch chance. Heat Wave is a spread move that is weaker, but can hit Pawniard super-effectively while retaining coverage on Grass types. Protect allows Vullaby to dodge Fake Outs to preserve its HP, and to wait for teammates to deal with unfavorable matchups. 
This Vullaby set can either punch holes in the enemy team early- to mid-game, or can act as a late-game sweeper once its checks are weakened or removed. The EV spread maximizes Vullaby's Special Attack, allowing it to hit as hard as possible, and gives it enough speed to outspeed the entire unboosted metagame after a Weak Armor boost. Eviolite allows Vullaby to take hits better, especially physical ones, to keep it in a good health range after getting +2 in both SpA and Spe.
This Vullaby requires some team support to work. Vullaby appreciates Pokemon that can deal with Onix, Pawniard and Spritzee, since those are Pokemon that Vullaby can't reliably deal with even after setting up. Therefore, Pokemon such as Mienfoo, Squirtle, Ponyta and Pawniard make good partners. Speed control is also important for Vullaby, since opposing Pokemon can still outspeed it and take advantage of its lowered Defense if Tailwind is up on their side, and Trick Room will turn Vullaby's increased Speed against it. The aforementioned Mienfoo and Pawniard can prevent opposing Pokemon from setting Tailwind and Trick Room with Taunt. Vullaby also appreciates if the physical hits it needs to take are weaker, so Will-o-Wisp users like Ponyta and Koffing, and Intimidate Pokemon like Scraggy can help in this regard. Finally, since Vullaby's defenses are dropped and HP is lowered after it has set up, it appreciates redirection from Foongus and Squirtle, or Fake Out support from the likes of Squirtle and Mienfoo, to keep it safe from attacks.