Clair & Kingdra

Kingdra is a very polite Pokemon because she doesn’t just help her own Team, she helps the Enemy Team as well by reducing her own Sp. ATK, and removing her own Buffs when removing Debuffs. 

Her stats are average across the board and while Rainy Day 2 is a great Passive Skill when Teamed with Rainy Day casters, there aren’t many arguments beyond that to add her to a Team. 

Powerful Monkey’s Paw Moves

Dragon Breath and Kingdra’s Sync Move are both pretty strong, and the former has a moderate chance of Paralyzing the Enemy. While Draco Meteor is also quite powerful, it and “X Sp. ATK” should be used in turns to ensure Kingdra’s Sp. ATK doesn’t drop too low. 

Counterintuitive

“Victory Is Mine!” may remove Debuffs, but it also her Buffs Buffs too, so “X Sp. ATK” shouldn’t be used unless all uses of “Victory is Mine!” are used to avoid canceling her own Buffs. The one advantage to this Move is that it increases Critical Hit Rate with each use. 

It doesn’t help anything that Draco Meteor also sharply reduces her Sp. ATK.

Weak to Self

In the main Pokemon series, it’s pretty normal for Dragons to be weak against Dragon Type Moves, but in Pokemon Masters where each Pokemon only has one weakness, Clair & Kingdra are actually the only currently playable Sync Pair weak to Dragon Type Moves. 

While there’s a more varied roster of Enemy Pokemon, Kingdra’s counterintuitive toolkit is just as much a disadvantage as the Enemy’s Moves. 

Rainy Day Teams

Her Racing Rain 2 Passive Skill makes Kingdra a good Teammate for Rainy Day casters. Her Speed isn’t too bad either, so It’s not likely to slow anyone down.