Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
Since Ditto won't work, you could make a wild Smeargle learn Substitute by using it with less than 25% health and then sketch it from the wild Smeargle. Wild Mr. Mime won't work since it's at too high of a level to know Substitute. According to the disassembly, the only trainer with Substitute...
Dudunsparce @ Protective Pads
Ability: Technician
Tera Type: Normal
EVs: 252 HP / 4 Atk / 252 SpD
Careful Nature
- Population Bomb
- Assurance
- Coil
- Roost
An idea for a bulky Coil + Population Bomb user. Coil makes Population Bomb never miss, so you can use Protective Pads. Even uninvested...
Bagon (Roaring Moon) @ Life Orb
Ability: Sheer Force
Tera Type: Steel
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Dragon Rush
- Crunch
- Iron Head
- Dragon Dance
Bagon has the cool and unique combination of Sheer Force + Dragon Dance, and Roaring Moon seems to be a decent fit for its...
I've made teams before, but I'm not a stellar player or team-builder. I've played on Showdown for a while but I'm not an expert or even that good by any means. My current Gen 7 Ubers rating is 1140. I think I do OK building purely offensive/defensive Pokémon but I can't put 4 attacking/boosting...
I'm surprised nobody has mentioned Tyranitar yet. Here are a bunch of Pokémon I looked at that could/might work as Leaders:
Abilities:
Sand Stream: Can be used to buff Rock-type defensive walls like Stakataka and Regirock.
Unnerve: Not that useful but could potentially hurt someone whose set...