Mothim

At first glance, Mothim seems to be outclassed by Butterfree and other Quiver Dance users due to its frailty and lack of Sleep Powder, but fortunately for Mothim, its decently high Special Attack and Tinted Lens ability typically make it a better user of Choice Specs than these Pokemon, though an inferior user of Quiver Dance. Even so, Mothim's low Speed, 4x weakness to Stealth Rock, and overall frailty make it hard for it to stay around for longer than a few turns, so its use is fairly limited. While it won't hurt to try Mothim out, you have to keep in mind that it faces a lot of competition as a wallbreaker from other Pokemon such as Charizard, who can provide other benefits to your team in addition to punching holes in opposing teams.