Tapu Koko

Tapu Koko is one of the best pivots in the tier, owing to its lightning-fast Speed, ability to generate momentum like none other with access to both Volt Switch and U-turn, and its sizable offensive presence that forces switches from common metagame threats like Tornadus-T and Weavile. It can threaten the tier's defensive Water-types and Flying-types like Slowbro, Toxapex, and Corviknight with ease and can even make good use of its resistances to Flying, Fighting, and Dark, keeping healthy with Roost and defensively checking the likes of Tornadus-T and Zapdos. It has the option to set up with Calm Mind, with its incredible Speed stat giving it an edge against offensive teams and making it challenging to revenge kill. Despite all of this, however, Tapu Koko's lackluster defensive stats and mediocre base Special Attack stat cannot be ignored, and faster Pokemon like Timid Choice Specs Dragapult and Choice Scarf Kartana are able to force it out.