The Mega (Sableye-Mega) @ Sablenite  
Ability: Prankster  
Tera Type: Dark  
EVs: 252 HP / 252 Def / 4 Spe  
Bold Nature  
IVs: 0 Atk  
- Calm Mind  
- Will-O-Wisp  
- Hex  
- Recover  

Mega at Heart (Talonflame) @ Heavy-Duty Boots  
Ability: Flame Body  
Tera Type: Fire  
EVs: 248 HP / 252 SpD / 8 Spe  
Careful Nature  
- Brave Bird  
- Taunt  
- Defog  
- Roost  

Probably Mega (Excadrill) @ Heavy-Duty Boots  
Ability: Sand Rush  
Tera Type: Ground  
EVs: 192 HP / 64 Def / 252 Spe  
Jolly Nature  
- Rapid Spin  
- Earthquake  
- Iron Head  
- Stealth Rock  

Mega's Left Cousin (Slowking-Galar) @ Heavy-Duty Boots  
Ability: Regenerator  
Tera Type: Poison  
EVs: 252 HP / 88 SpA / 168 SpD  
Calm Nature  
IVs: 0 Atk  
- Chilly Reception  
- Future Sight  
- Sludge Wave  
- Thunder Wave  

The Real Mega (Chesnaught) @ Rocky Helmet  
Ability: Bulletproof  
Tera Type: Grass  
EVs: 252 HP / 4 Def / 252 SpD  
Impish Nature  
- Knock Off  
- Body Press  
- Iron Defense  
- Leech Seed  

DONT Let Him Mega (Alakazam) (M) @ Focus Sash  
Ability: Magic Guard  
Tera Type: Psychic  
EVs: 4 HP / 252 SpA / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Nasty Plot  
- Psychic  
- Focus Blast  
- Counter