Calyrex-Shadow @ Focus Sash  
Ability: As One (Spectrier)  
Level: 50  
Tera Type: Ghost  
EVs: 252 SpA / 4 SpD / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Psychic  
- Astral Barrage  
- Encore / Nasty Plot
- Protect  

Koraidon @ Life Orb  
Ability: Orichalcum Pulse  
Level: 50  
Tera Type: Fire  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Flame Charge  
- Flare Blitz  
- Close Combat  
- Protect  

Chi-Yu @ Choice Scarf
Ability: Beads of Ruin
Level: 50
Tera Type: Ghost
EVs: 252 SpA / 4 SpD / 252 Spe
Modest Nature
- Heat Wave
- Dark Pulse
- Overheat
- Snarl

Ogerpon-Hearthflame (F) @ Hearthflame Mask  
Ability: Mold Breaker  
Level: 50  
Tera Type: Fire  
EVs: 28 HP / 76 Atk / 44 Def / 108 SpD / 252 Spe  
Jolly Nature  
- Follow Me  
- Spiky Shield  
- Ivy Cudgel  
- Wood Hammer / Power Whip  

Iron Bundle @ Booster Energy  
Ability: Quark Drive  
Level: 50  
Tera Type: Ghost  
EVs: 52 HP / 44 Def / 4 SpA / 156 SpD / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Freeze-Dry  
- Icy Wind  
- Protect  
- Encore  

Flex slot as the last slot, some ideas include:

Iron Hands @ Assault Vest
Ability: Quark Drive
Level: 50
Tera Type: Water
EVs: 76 HP / 180 Atk / 12 Def / 236 SpD 
Brave Nature
- Drain Punch
- Wild Charge
- Fake Out
- Low Kick / Heavy Slam

Chien-Pao @ Life Orb
Ability: Sword of Ruin
Level: 50
Tera Type: Ghost
EVs: 252 Atk / 4 Def / 252 Spe 
Jolly Nature
- Sucker Punch
- Ice Spinner
- Crunch
- Protect

Whimsicott @ Covert Cloak
Ability: Prankster
Level: 50
Tera Type: Ghost
EVs: 180 HP / 108 SpD / 220 Spe 
Timid Nature
IVs: 0 Atk 
- Moonblast
- Sunny Day
- Tailwind
- Encore

Indeedee-F @ Psychic Seed
Ability: Psychic Surge
Level: 50
Tera Type: Fairy
EVs: 252 HP / 252 Def / 4 SpD 
Bold Nature
IVs: 0 Atk 
- Dazzling Gleam
- Follow Me
- Helping Hand
- Trick Room