Rate my Mono-Water team

Question

Azumarill @ Sitrus Berry
Ability: Huge Power
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Belly Drum
- Aqua Jet
- Play Rough
- Waterfall

Greninja @ Expert Belt
Ability: Protean
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Ice Beam
- Dark Pulse
- Surf
- Extrasensory

Swampert @ Assault Vest
Ability: Torrent
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Earthquake
- Outrage
- Mega Kick
- Waterfall

Rotom-Wash @ Leftovers
Ability: Levitate
EVs: 252 HP / 4 SpA / 252 SpD
Calm Nature
- Volt Switch
- Thunder Wave
- Confuse Ray
- Dark Pulse

Cloyster @ White Herb
Ability: Skill Link
EVs: 4 Atk / 252 SpA / 252 Spe
Rash Nature
- Shell Smash
- Icicle Spear
- Surf
- Signal Beam

Sharpedo @ Life Orb
Ability: Speed Boost
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Protect
- Crunch
- Waterfall
- Earthquake

Comments

Ditch Mega Kick and Outrage off Swampert for like Stone Edge and Ice Punch or something along those lines.
Cloyster should not be running a largely special set, change it to a more physically based set. Replace Surf with Razor Shell, Signal Beam with Rock blast.
Sharpedo you could consider running a mix variant.
It would probably be better to run Standard OU Rotom rather than your set. Confuse Ray is shaky, and Dark Pulse has little coverage and Hydro Pump hits just as hard as a super effective Dark Pulse.
Consider Scald or Hydro Pump over Surf for the Burn chance / Power.

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Consider Mega or SubDD bulky guarados over greninja, and Lanturn over rotom-w

As a mono water, it gets predictable if you keep on switching in swampert for electric attacks. Lanturn gets volt absorb and is really bulky, so it works.