View all the monotype teams here: https://pastebin.com/S419KvS5
 
Pokemon Battle Tower Monotype team challenge
WATER team
Version: 2.0
Gold symbol achieved! (Video coming soon)
 
S (Starmie) @ Lum Berry
Ability: Natural Cure
Level: 50
EVs: 4 HP / 252 SpA / 252 Spe
Modest nature  
IVs: 31 HP / 31 Atk / 31 Def / 31 SpA / 31 SpD / 31 Spe  
- Surf
- Psychic
- Thunderbolt
- Ice Beam
 
C (Cloyster) @ Salac Berry
Ability: Shell Armor
Level: 50  
EVs: 68 Atk / 196 SpA / 244 Spe
Rash nature  
IVs: All 31
- Surf
- Ice Beam
- Endure
- Explosion
 
S (Swampert) @ Choice Band
Ability: Torrent
Level: 50  
EVs: 4 HP / 252 Atk / 4 Def / 40 SpD / 208 Spe
Adamant nature  
IVs: 31 HP / 31 Atk / 31 Def / 31 SpA / 30 SpD / 30 Spe 
- Earthquake
- Rock Slide
- Hidden Power [Bug]
- Return
 
Notes:
- Starmie is preferred to Calm Mind Suicune because it speeds up wins considerably
- Cloyster replaces Leftovers Gyarados from the old team. It has perfect coverage and can outspeed and OHKO almost every Pokemon in the game thanks to Salac Berry. Riskier than Gyarados but much faster.
- Choice Band is given to Swampert because it gives a lot of Earthquake OHKOS, plus it can't do much else (Surf/Ice Beam don't complement Starmie and Gyarados' moves well, and Cursepert is just bad)
- Electric types: Switch to Swampert and EQ