NFE Choiced (Rufflet) (M) @ Choice Scarf / Choice Band
Ability: Hustle  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Brave Bird  
- Superpower / Return
- Aerial Ace / Return
- U-turn / Return
NFE SpDef Bulk Up (Rufflet) @ Eviolite  
Ability: Hustle  
EVs: 120 HP / 252 SpD / 136 Spe  
Careful Nature  
- Aerial Ace  
- Bulk Up  
- Roost  
- Superpower 
Optional Move(s): 
- Defog 
- Facade
- Hone Claws
Optional Item(s): 
- Flyinium Z
Optional Ability: 
- N/A
Optional EV/IV(s):  
- 252 Atk / 4 SpD / 252 Spe (Adamant)
Overview: Thanks to Hustle, Rufflet can act as a potent wallbreaker and cleaner for offensive teams. It can also act as a bulky wincon courtesy of its Bulk Up set. However, Rufflet's Choice Band and Scarf sets face heavy competition from Staravia, who has better speed and 100% accurate attacks. Rufflet's niche over Staravia is greater power and coverage for Steel-type Pokemon in Superpower, which is something Staravia lacks.
Choice Scarf: Choice Scarf Rufflet outspeeds the entire unboosted metagame including notable threats such as Electabuzz, Frogadier, Haunter, and Kadabra, and still hits opposing Pokemon hard thanks to Hustle. Brave Bird OHKOs Fighting- and specially defensive Grass-types such as Monferno, Machoke, and Servine, and hits most neutral targets hard. Superpower hits Steel-types such as Metang, Pawniard, and Lairon for super effective damage. Return provides a good neutral STAB attack against most of the metagame and does not have recoil damage. Aerial Ace is weaker than Brave Bird, but it provides Rufflet with a STAB attack that never misses and it deals good damage to super effective or frail targets. U-turn lets Rufflet get momentum and useful chip damage on expected switch-ins. 
Choice Band: Choice Band Rufflet gives up speed for incredible wallbreaking power and easily 2HKOs even the bulkiest of physical walls with its attacks.
SpDef Bulk Up: The Bulk Up Rufflet set acts a late-game wincon. It can set up on the likes of Clefairy, Metang, defensive Staravia, defensive Roselia, and on forced switch-ins. Bulk Up boosts Rufflet's Attack and Defense. Roost provides Rufflet with the longevity needed to set up and tank hits. 
Checks and Counters
Choice Scarf / Choice Band: Very little can switch into either the Choice Scarf or Choice Band set. Metang can eat one Choice Band boosted attack or unboosted Superpower and threaten or cripple it in return. Non-Eviolite Rufflet sets are very frail so, if Rufflet cannot kill whatever is in front of it, it may get knocked out in return. Thanks to Hustle, Rufflet can also miss attacks, which is usually detrimental to it if it's trying to wallbreak or revenge kill an opposing Pokemon. Faster Choice Scarf users such as Electabuzz, Frogadier, and Monferno, as well as Focus Sash users like Kadabra cannot switch into Rufflet but can revenge kill it. Stealth Rock and Brave Bird recoil damage also limit the amount of work Rufflet can put in and puts it on a timer.
SpDef Bulk Up: The Bulk Up set is less susceptible to being revenge killed by fast special attackers but Pokemon such as Mareanie and Dusclops can Haze all boosts away. This Rufflet set is also very susceptible to Toxic.