The best Fairy type is probably Mimikyu because it has solid Attack and Speed. In addition, its Ability gives you a free turn to do whatever you want, it gets strong moves like Shadow Sneak and Play Rough, and its typing is one of the better offensive combinations in the game.
The only consistent issue is that Disguise chip and Wood Hammer recoil are prone to whittling it down, so you'll need to keep a supply of healing items on hand.
Mimikyu
Ability: Disguise
- Play Rough (Level 54)
- Shadow Claw (Level 42)
- Shadow Sneak (Level 6)
- Wood Hammer (Level 1)
There are other good Fairy types like Gardevoir and Grimmsnarl, but I like Mimikyu best because Ghost is a spammable STAB type and Disguise is one of the best crutches available. I think Flutter Mane is much better if you'd like to replace Mimikyu after The Way Home, however. For Violet players, Iron Valiant is also a better choice.
