Clefable

Clefable is one of the old-school defenders, but now it's pretty underwhelming. With Steel Type titans like Shadow Metagross and Dawn Mane Necrozma waiting to smack it with some cold metal, Clefable really doesn't work extremely well.

Best PvE Offensive Moveset

• Fairy Wind slightly out-paces Charm on average, and is also easier to dodge with.
• Zen Headbutt can pair with Psychic, but Clefable isn't good in this role.
• Dazzling Gleam is better than Moonblast for Fairy Type damage output.
• Charge Beam, Pound*, Meteor Mash, and Swift are all underwhelming for Clefable.

Best PvE Defensive Moveset

• Charm out-paces all of the competition, hitting very hard on defense.

• Zen Headbutt isn't the worst Fast Move on defense, but it generally falls behind Charm.

• Charge Beam and Fairy Wind aren't the worst, but they're definitely behind the competition by way of Fast Moves.

• Psychic, Meteor Mash, or Dazzling Gleam are the best Charged Move options on defense, as each has its own set of advantages.

• Swift and Moonblast fall behind.

Clefable can opt for two playstyles - one that focuses on firing hard-hitting charge moves, and another that focuses on consistent, relentless Fairy-type damage.

Fairy Wind's high energy generation combines well with Meteor Mash and Moonblast, two excellent charge moves. This is usually the preferred moveset, as Clefable tends to compete with other Charmers.

Charm enables Clefable to deal Fairy-type damage without relying on charge moves. 

Swift is by far Clefable's cheapest Charged Attack; it is an excellent bait move and can also be used to finish off weakened targets. Moonblast is typically the preferred Charged Attack (mandatory on the Fairy Wind set) due to its high DPE and STAB. Meteor Mash is an option that can break apart opposing Fairy-type Pokemon. Psychic can be used to pressure Poison-type Pokemon, but should only be used on the Charm set, where Clefable already deals significant Fairy-type damage. Dazzling Gleam is strictly inferior to Moonblast.