Klefki

Klefki's excellent typing allows it to check a myriad of top-tier threats such as Kyurem-B, Hoopa-U, Weavile, and Latios. While Klefki forces these Pokemon out, it is able to reliably set up Spikes for offensive teams. Thunder Wave is one of Klefki's biggest assets, as many offensive teams love having a priority Thunder Wave user to cripple fast threats such as Weavile, Serperior, and boosted Mega Scizor, which otherwise threaten to sweep after setting up. Klefki is very unpredictable as well, as it can pick from two coverage moves to limit its counters, and it has the ability to run wonderful utility moves such as Magnet Rise, Moonlight, and King's Shield. Prankster is one of the best abilities in the game, and Klefki has the perfect movepool to utilize it. However, although Thunder Wave is a great move, many Pokemon, such as Landorus-T, Thundurus, and Diggersby, are immune to it, thus leaving Klefki as setup fodder for these Pokemon. Klefki is also very weak to Ground-type moves, and although this can be mitigated with Magnet Rise, it takes a turn to use, and Klefki is unable to switch into Ground-types otherwise. Klefki has a large movepool, but it often can't accomplish everything it wants to due to its inability to fit everything it wants into one set. Finally, Klefki has absolutely no offensive presence, which leaves it unable to threaten setup sweepers immune to Thunder Wave.