View all the monotype teams here: https://pastebin.com/S419KvS5
 
Pokemon Battle Tower Monotype team challenge
PSYCHIC team
Version: 1.0
 
L (Latios) @ Lum Berry
Ability: Levitate
Level: 50  
EVs: 4 HP / 252 SpA / 252 Spe
Modest nature  
IVs: 31 HP / 0 Atk / 31 Def / 31 SpA / 31 SpD / 31 Spe  
- Psychic
- Thunderbolt
- Dragon Claw
- Surf

M (Metagross) @ Liechi Berry
Ability: Clear Body
Level: 50
EVs: 4 HP / 252 Atk / 252 Spe
Adamant nature  
IVs: 31 HP / 31 Atk / 31 Def / 31 SpA / 31 SpD / 31 Spe  
- Meteor Mash
- Earthquake
- Shadow Ball
- Explosion
 
M (Medicham) @ Choice Band
Ability: Pure Power
Level: 50
EVs: 4 HP / 252 Atk / 252 Spe
Adamant nature  
IVs: 31 HP / 31 Atk / 31 Def / 31 SpA / 31 SpD / 31 Spe 
- Fake Out
- Brick Break
- Shadow Ball
- Rock Slide
 
Notes:
- This team opts for speed over safety. Medicham is riskier than Latias but speeds up a lot of battles against Normal and Dark types thanks to its massive Attack of 246. You can switch into Medicham and OHKO Blissey, Snorlax, Umbreon, Regice and sometimes even Registeel with minimal risk. Also, Metagross runs Liechi Berry instead of the slower Leftovers.
- Latios primarily struggles against Ice types, but Metagross and Medicham handle them easily. Sometimes it's fine to let Latios die and then bring in Medicham to sweep with Brick Break, as trainers with Ice Pokemon are often weak to Fighting moves.
- Fake Out is this team's solution to Flail and Reversal users, and it's also an effective revenge kill against Pokemon that outspeed Medicham.