Whimsicott

Fairy Wind + Grass Knot and Moonblast

Charm + Seed Bomb and Moonblast or Hurricane

Fairy Wind provides Whimsicott the energy gain to reach its rather expensive Charged Attacks and utilize its rather unique coverage.

Both Charm and Razor Leaf sport the highest damage output from fast moves in the game, but also tie for the worst energy generation. Charm is generally preferred, as many other Grass-type Pokemon have access to Razor Leaf.

Seed Bomb costs the least amount of energy among Whimsicott's charge moves and benefits from STAB, but its damage can be lacking. Charm Whimsicott should run Seed Bomb to compensate for Charm's low energy gain. Grass Knot costs slightly more energy but deals considerably more damage; it is the preferred Grass option if running Fairy Wind. Moonblast costs 5 less energy than Hurricane, but both are very slow to access and are different typings. Either can be chosen, though poor energy generation may limit access to them.