Other Metagames Monotype Water Team

[GengarGallows]

So I'm really new to competitive battling and I was wondering if I could get a rating on my water monotype team?

Swampert W/ Leftovers
Ability: Damp
EVs: 252 HP / 4 Atk / 252 Def
Impish Nature
- Stealth Rock
- Earthquake
- Scald
- Toxic

Gyarados-Mega (M) W/ Gyaradosite
Ability: Intimidate
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Dragon Dance
- Crunch
- Waterfall
- Earthquake

Slowking (M) W/ Leftovers
Ability: Regenerator
EVs: 252 HP / 4 Atk / 252 Def
Relaxed Nature
- Scald
- Slack Off
- Dragon Tail
- Psyshock

Carracosta W/ Leftovers
Ability: Solid Rock
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Stealth Rock
- Scald
- Rock Slide
- Aqua Jet

Lapras W/ Leftovers
Ability: Water Absorb
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
- Hydro Pump
- Ice Beam
- Freeze-Dry
- Protect

Keldeo-Resolute W/ Choice Specs
Ability: Justified
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Scald
- Secret Sword
- Hydro Pump
- Icy Wind