Politoed @ Leftovers
Trait: Drizzle
EVs: 252 Def / 252 HP / 4 Spd
Bold Nature
- Scald
- Protect
- Toxic
- Refresh

Politoed sets up the Rain and can also use a powered up Scald to heavily damage and burn opponents. It has Refresh to cure Status like Toxic, as that would be the main way of dealing with it, since it has maxed out Physical Defense and also good Special Defense. In turn, it can use Toxic on other Bulky Pokemon and use Protect to ease prediction.

Keldeo-Resolute @ Choice Specs
Trait: Justified
EVs: 252 Spd / 252 SAtk / 4 SDef
Timid Nature
- Secret Sword
- Hydro Pump
- Hidden Power [Ice]
- Surf

Keldeo can deal with all other Pokemon who can set up weather using their Abilities. Tyranitar and Abomasnow are defeated in one hit with Secret Sword. Hippowdon and Ninetales are defeated by Surf / Hydro Pump. It has Hidden Power Ice to deal with the strong Dragon Types of Overused, like Garchomp and Dragonite. Hydro Pump is used for extra power, while Surf is used when Accuracy is more important than damage.

Tentacruel @ Black Sludge
Trait: Rain Dish
EVs: 236 Def / 252 HP / 20 Spd
Bold Nature
- Rapid Spin
- Scald
- Toxic Spikes
- Ice Beam

Tentacruel can heal a lot of damage in the Rain, combining Black Sludge and Rain Dish. It has Rapid Spin to deal with Entry Hazards, especially Stealth Rock, which Thundurus-T loathes. In turn, it can set up its own Entry Hazard in the form of Toxic Spikes. It has Scald to damage and potentially Burn the opponent, while Ice Beam can deal with strong Dragon Types and also Gliscor.

Thundurus-Therian (M) @ Life Orb
Trait: Volt Absorb
EVs: 188 Spd / 252 SAtk / 68 Def
Modest Nature
- Agility
- Grass Knot
- Thunder
- Hidden Power [Ice]

The abuldance of Water Type Pokemon in this team leaves it vulnerable to Electric Type Moves, especially Thunder, which gets 100% Accuracy in the Rain. Agility can be used for some extra Speed, which makes Thundurus even faster. Grass Knot can be used to deal with Tyranitar, which would defeat Thundurus otherwise and Thunder can be used to deal with opposing Water Types who take advantage of our Rain. Hidden Power Ice can be used to deal with strong Dragon Types and Gliscor, along with opposing Grass Types, which this set loathes.

Scizor @ Choice Band
Trait: Technician
EVs: 252 Atk / 248 HP / 8 SDef
Adamant Nature
- Bullet Punch
- Pursuit
- U-turn
- Superpower

Scizor's only weakness is Fire Type Moves, which are weakened with the help of the Rain. U-Turn can be used to deal heavy damage with Technician and Choice Band and also to avoid getting locked into one Move. Bullet Punch can be used for a decent 60 Power Priority Move, with the help of Technician. Superpower does imense damage with Choice Band and also defeats Tyranitar in one hit, while Pursuit exists to catch the opposing Psychic Type, who try to switch, off guard.

Jirachi @ Leftovers
Trait: Serene Grace
EVs: 252 HP / 156 Spd / 100 Def
Timid Nature
- Calm Mind
- Substitute
- Psyshock
- Thunder

Jirachi can switch into something which cannot harm it and it sets frighteningly easily due to its large amount of resistances and overall great bulk. It can set up 4 Substitutes with maxed out Hp and potentially more due to Leftovers. Substitutes, while protecting it from Status, also prevents it from being defeated in one turn, after which it can potentially defeat the opponent in one turn with enough Calm Mind boosts. Psyshock deals with Pokemon whose Special Defense is too high, like Blissey and Chansey and can also be used for coverage.
Thunder gets maximum Accuracy in the Rain, has a very high Power and has a 60% Chance of Paralyzing the opponent due to Serene Grace.