Yamask

At a glance, Yamask doesn't look particularly special. It has a generic Ghost typing, a shallow movepool, and low Speed. However, it does bring a few useful moves, such as Trick Room and Nasty Plot, and an interesting new ability to the table. With these tools in tandem with its great defenses and usable Special Attack, Yamask can play a couple of roles reasonably well, the most effective one being that of a Trick Room abuser. While Yamask certainly isn't winning any awards for creativity, it can at least become a dangerous sweeper when given the opportunity to set up.