This is my steel gym team:

Solgaleo @ Leftovers
Ability: Full Metal Body
Tera Type: Steel
EVs: 252 HP / 96 Atk / 160 SpD
Impish Nature
- Sunsteel Strike
- Earthquake
- Thunder Wave
- Morning Sun

Gholdengo @ Air Balloon
Ability: Good as Gold
Tera Type: Steel
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
IVs: 0 Atk
- Make It Rain
- Shadow Ball
- Recover
- Nasty Plot

Ability: Intrepid Sword
Tera Type: Steel
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Behemoth Blade
- Sacred Sword
- Swords Dance
- Play Rough

Ability: Iron Barbs
Tera Type: Grass
EVs: 252 HP / 88 Def / 168 SpD
Relaxed Nature
IVs: 0 Spe
- Stealth Rock
- Leech Seed
- Gyro Ball
- Protect

Magearna @ Leftovers
Ability: Soul-Heart
Tera Type: Steel
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
IVs: 0 Atk
- Fleur Cannon
- Volt Switch
- Pain Split
- Psyshock

Corviknight (M) @ Leftovers
Ability: Pressure
Tera Type: Flying
EVs: 252 HP / 168 Def / 88 SpD
Impish Nature
- Defog
- Roost
- Body Press
- U-turn