Hello. For the most part, you have 4 viable Pokemon on the team being Mega Swampert, Gyarados, Rotom-Wash, and Toxapex. These Pokemon just need to have their sets fixed. The other two Pokemon, Basculin and Politoed, will be replaced by Greninja and Pelipper, respectively. So, here is the team rate:
Mega Swampert
Since this team doesn't have Seismitoad, Mega Swampert should use Stealth Rock over Rock Slide. That way, your team can have a Stealth Rock setter.
Swampert-Mega @ Swampertite
Ability: Swift Swim
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Stealth Rock
- Waterfall
- Earthquake
- Ice Punch
Gyarados
Gyarados doesn't use Focus Sash or Ice Fang. It should also use Jolly Nature so it can outspeed more Pokemon. Gyarados should use a Dragon Dance set with Waterfall, Bounce, and Taunt/Substitute with Flyinium Z. That set allows Gyarados to break past certain Pokemon such as Mega Venusuar, a problematic Pokemon for Water teams. Here is the set:
Gyarados @ Flyinium Z
Ability: Moxie
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Dragon Dance
- Bounce
- Waterfall
- Taunt / Substitute
Taunt is used to help break down defensive teams, while Substitute allows Gyarados to setup on Pokemon using weak attacks against it. Earthquake is an option over Taunt/Substitute to allow Gyarados to hit Electric- and Poison-types super effectively.
Basculin -> Greninja
Unfortunately, Basculin isn't good in Gen 7 Monotype. Basuclin's base 92 Attack with no move to boost it makes it not a strong wallbreaker in the Monotype meta. I replaced Basuclin with Greninja for the Choice Scarf user, as its Protean ability allows it to handle lots of Pokemon while still doing a good amount of damage. Greninja's base speed of 122 is useful to outspeed other Choice Scarf users such as Latias, Gengar, Blacephalon, and Victini. Here is the set:
Greninja @ Choice Scarf
Ability: Protean
EVs: 4 Atk / 252 SpA / 252 Spe
Naive Nature
- U-turn
- Ice Beam
- Gunk Shot
- Dark Pulse / Rock Slide
Ice Beam is useful for the Dragon matchup, and Gunk Shot is used to target Fairy-types such as Tapu Koko, Tapu Fini, and Azumarill. Rock Slide can be used over Dark Pulse to nail Mega Charizard Y and Volcarona. There are other coverage options, such as Low Kick for Pokemon like Kyurem-B, Tyranitar, and Heatran, and Hidden Power Fire for Pokemon such as Ferrothorn and Scizor.
Rotom-Wash
The set is fine, but Rotom-Wash should use Pain Split over Defog since Pelipper will be the rain setter. Pain Split is also Rotom-Wash's only form of HP recovery, so using Defog Pelipper allows Rotom-Wash to use Pain Split. Rotom-Wash should also use a physically defensive EV spread so it can have a better time against physical wallbreakers such as Garchomp, Mamoswine, and Victini. Here is what the set looks like with those revisions:
Rotom-Wash @ Leftovers
Ability: Levitate
EVs: 248 HP / 216 Def / 44 Spe
Bold Nature
IVs: 0 Atk
- Volt Switch
- Hydro Pump
- Pain Split
- Will-O-Wisp
248 HP EVs help it vs Stealth Rock since the total HP is 303, an odd number. 44 Speed EVs is use to let Rotom-Wash outspeed Jolly Azumarill so it can burn it.
Politoed -> Pelipper
Pelipper is the better rain setter due to it having a STAB Hurricane to deal with Grass-types such as Mega Venusuar and Tapu Bulu. Pelipper can either use a Choice Specs or a defensive set, both of them using Defog. Since the Politoed you had was offensive, I'll just be posting the Choice Specs set:
Pelipper @ Choice Specs
Ability: Drizzle
EVs: 4 Def / 252 SpA / 252 Spe
Timid / Modest Nature
- Hurricane
- Hydro Pump
- U-turn
- Defog
Timid Nature allows Pelipper to outspeed slower Pokemon such as Tapu Bulu, while Modest Nature gives Pelipper more power.
Toxapex
Toxapex never uses any other ability other than Regenerator. Regenerator making Toxapex recover HP when switching out makes it a really good defensive pivot, which is actually fine on this team considering you already have a Rotom-Wash for a defensive pivot. Not using Regenerator as the ability hinders Toxapex's defensive capabilities. Black Sludge is generally preferred over Rocky Helmet since the grudual HP recovery each turn is nice. Toxic is fine, though Toxapex can setup Toxic Spikes rather easily. Baneful Bunker should be replaced with Haze since this team doesn't have Haze Mantine to get rid of the boosts from setup sweepers. Here is what the set looks like with the changes:
Toxapex @ Black Sludge
Ability: Regenerator
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Scald
- Haze
- Toxic Spikes / Toxic
- Recover
The final team revisions can be found here.
Hope this helps! :)
