Durant

Durant has the unique combination of Hustle, First Impression, and a solid Speed stat, making it seem appealing as a niche wallbreaker and revenge killer, It's able to revenge kill common Pokemon like Nihilego and Cobalion, as well as OHKOing faster threats like Azelf, Choice Scarf Hydreigon, and Zygarde-10%. It also possesses other good attacks like Rock Slide to hit Salamence and Rotom-H, Superpower to KO Cobalion, and Iron Head to better threaten the likes of Nihilego, Mamoswine, and Hatterene. However, it's near-entirely outclassed by fellow Bug / Steel type Scizor, and to a lesser extent Cobalion. Besides those two providing utility options like pivoting, Knock Off, and Stealth Rock, both have much better defensive presences. In practice, Durant fails to come in safely and efficiently wallbreak, since it has poor bulk and can't significantly damage common Pokemon like Rotom-W and Slowking after it uses First Impression. It is also easily worn down through Life Orb recoil, Rocky Helmet users like Skarmory and Amoonguss, and entry hazards. Hustle also makes Durant incredibly inconsistent as a wallbreaker, and since it is incredibly frail, it is likely to be KOed in the same turn after missing a move.