Tapu Koko

Electric

Tapu Koko is one of Electric's deadliest wallbreakers and revenge killers due to its amazing Electric / Fairy STAB combination and its ability to amplify the power of Electric-type moves through Electric Surge. Fairy-type STAB is amazing for Tapu Koko, as it can reliably threaten Dragon-types like Kommo-o, Kyurem-B, and Hydreigon that are often very problematic for Electric teams to handle. Its blistering base 130 Speed tier allows it to outspeed unboosted threats such as Latios, Mega Gallade, and Dugtrio. It's a staple for all Electric teams, as the Electric Terrain provided by Electric Surge boosts the power of all Electric-type moves by 50%. Electric Terrain also provides smaller niches in preventing Spore and Sleep Powder from Breloom and Mega Venusaur from affecting all grounded Pokemon. Tapu Koko can also function as a powerful anti-lead option with Taunt to shut down entry hazard setters and setup sweepers and Volt Switch or U-turn to provide offensive momentum for itself and its teammates. However, despite being powerful, Tapu Koko is quite frail, and can often be KOed by threats such as Tapu Bulu and +2 Mega Scizor. Because Electric teams constantly rely on Tapu Koko's ability to set the Electric Terrain, it must be switched in very often to keep offensive pressure, which can be taken advantage of by the opponent.

Fairy

Tapu Koko is the fastest Pokemon available to Fairy teams, being able to outspeed almost all of the unboosted metagame. It also works as a fantastic offensive pivot, as it is able to gain momentum with U-turn. Due to its great Speed, it is also a fantastic revenge killer, which allows it to take on typical threats to Fairy such as Landorus, and Taunt allows it to shut down nearly every wall and prevent them from recovering off damage or prevent Pokemon such as Jirachi from setting up Stealth Rock. It is also blessed with a great offensive typing, allowing it to take on key threats to Fairy such as Celesteela. Tapu Koko is extremely valuable in the Water- and Flying-type matchup, as it can take on common threats such as Toxapex, Mantine, and Celesteela. However, Tapu Koko's Special Attack is lackluster when it isn't using Electric STAB moves, as it can't even OHKO Pokemon such as Gliscor with Hidden Power Ice, leaving it reliant on Thunderbolt to get across notable damage. Its lackluster bulk also leaves much to be desired, allowing it to be revenge killed rather easily by priority move users like Dragonite, faster Pokemon like Mega Aerodactyl, or bulky attackers that can take it on like Kyurem-B.