Comfey

Aloha from Hawaii! That's where you can find this Pokemon in Pokemon Go, making it a rare regional exclusive. Fortunately, it has no use in the meta, so a mere Dex entry is good enough if you can manage to get one. 

Best PvE Offensive Moveset

• Vine Whip lacks STAB, but at least it's stronger than the other option....
• Hidden Power can't be Fairy typing, which means Comfey will not get STAB on this move, making it an even worse choice.
• Grass Knot can pair with Vine Whip for a Grass-type role, but it's better to use actual Grass Pokemon.
• Petal Blizzard is a step down.
• Draining Kiss is a weak move, despite being stronger with STAB, and lacks moveset synergy.

Best PvE Defensive Moveset

• Hidden Power is more valuable on defense due to its higher base power and unpredictable typing. 
• Vine Whip is quite poor for defense, and its typing is not valuable for Comfey.
• Draining Kiss is arguably better for defense due to common Fighting-type attackers, as well as its faster damage window.
• Grass Knot hits harder but is easier to dodge.
• Petal Blizzard takes a long time to access, and Comfey might faint by then. 

Comfey has no viable movesets, but Vine Whip can still be used to generate energy decently fast. The unpredictable typing of Hidden Power can catch unsuspecting opponents off guard, but you can only fool your opponent once. In addition, Hidden Power can't be Fairy-type, which means no STAB. 

Grass Knot costs the least amount of energy, though still moderately expensive, and synergizes well to threaten common Water-types. Draining Kiss benefits from STAB and offers Fairy typing coverage, but its damage output is poor for its unappealing energy cost. Petal Blizzard demands too much energy.