Venomoth

Despite its RUBL status, Venomoth is an extremely potent Pokemon when used correctly. It's often thought that Venomoth is a high-risk / high-reward Pokemon, but this isn't exactly the case, as it's more along the lines of a mid-risk / very high-reward. It doesn't need in-battle support to work properly, just the right teammates so it can support them instead. And while it will absolutely wreck you if you underestimate it, don't overestimate it either, because it isn't all that easy to use due to its lack of bulk, which makes it hard to set up and restricts teammate options.