Klefki

Klefki's massive utility movepool alongside its Prankster ability makes it a premier support Pokemon in the UU metagame and the best user of Spikes by far. Its amazing defensive typing alongside access to moves like Thunder Wave and Magnet Rise allows it to very adequately check top-tier threats, such as Mega Aerodactyl, Latias, Mega Beedrill, and Hydreigon. Klefki also possesses a lot of flexibility in terms of which moves it can opt to run, which, alongside its ability to set up Spikes, allows it to fit very comfortably on offensive and balanced teams alike. Unfortunately, Klefki lacks recovery, which in tandem with its subpar bulk leaves it prone to being worn down, thus preventing it from reliably checking foes it aims to check from time to time. Klefki also lacks an offensive presence, which leaves it reliant on hitting foes super effectively to avoid being too passive.