Tapu Koko

Gen 7 is finally upon us and Tapu Koko leads the way! Unfortunately its stats are somewhat lackluster compared to existing Electric-type attackers, making this Pokemon more suitable as a Dex filler.

The addition of Nature's Madness on its movepool makes Tapu Koko a solid choice as a Fairy attacker even though it lacks a Fairy-type Fast Attack. It has less competition in this role compared to being an Electric attacker. However, as the move is an Elite move, it may not be readily available without using an Elite Charged TM.

In the main series, Tapu Koko is capable of learning Fairy Wind. If it gets it one day in Pokemon GO, Tapu Koko can become significantly stronger as a Fairy attacker.

Best PvE Offensive Moveset

• Volt Switch performs well on offense with STAB. 
• Quick Attack can't be Super Effective vs anything, but sometimes synergizes better with Nature's Madness because it is not resisted by Dragon-type Pokemon
• Nature's Madness* turns Tapu Koko into a respectable Fairy attacker despite lacking a Fairy-type Fast Attack.
• Thunderbolt outperforms Thunder in terms of overall performance and consistency. 
• Dazzling Gleam lacks synergy with Tapu Koko's Fast Moves and is severely outclassed by Nature's Madness
• Brave Bird is better suited for Flying-types. 

Volt Switch has superior stats in both damage output and energy generation compared to Quick Attack, not to mention STAB.

Nature's Madness is Tapu Koko's cheapest Charged Attack and is a reliable source of Fairy STAB; it also deals decent damage and comes with a guaranteed Defense debuff on the opponent. Thunderbolt is moderately expensive, but it is Tapu Koko's cheapest Electric STAB. Thunder is slightly stronger for slightly more energy, but adding further energy costs is undesirable. Brave Bird can be used as a surprise move choice, dealing heavy damage to Grass- and Ground-type Pokemon, but it sacrifices one of Tapu Koko's good STAB options and it comes with a nasty self-debuff. Dazzling Gleam is largely outclassed by Nature's Madness