Thundurus (M) @ Flyinium Z  
Ability: Defiant  
Level: 50  
EVs: 4 HP / 252 Atk / 252 Spe  
Jolly Nature  
IVs: 0 SpA  
- Wild Charge  
- Protect  
- Fly  
- Superpower

Unown
Offensive calcs:
- +1 252 Atk Thundurus Superpower vs. 236 HP / 4 Def Incineroar: 204-240 (102 - 120%) -- guaranteed OHKO
- +1 252 Atk Thundurus Supersonic Skystrike (175 BP) vs. 4 HP / 0 Def Landorus-T: 225-265 (136.3 - 160.6%) -- guaranteed OHKO
- 252 Atk Thundurus Supersonic Skystrike (175 BP) vs. 252 HP / 0 Def Mega Rillaboom: 254-300 (122.7 - 144.9%) -- guaranteed OHKO

Thundurus (M) @ Sitrus Berry  
Ability: Prankster  
Level: 50  
EVs: 252 HP / 244 Def / 12 SpD  
Bold Nature  
IVs: 0 Atk  
- Thunderbolt  
- Eerie Impulse  
- Thunder Wave  
- Taunt

Unown
Move options:
- offensive: Hidden Power Ice
- supportive: Protect, Scary Face, Electroweb

Unown
Defensive calcs:
- 252 Atk Urshifu-Rapid Strike Surging Strikes (3 hits) vs. 252 HP / 244+ Def Thundurus on a critical hit: 93-111 (50 - 59.6%) -- guaranteed 3HKO after Sitrus Berry recovery
- 252+ Atk Glastrier Icicle Crash vs. 252 HP / 244+ Def Thundurus: 156-186 (83.8 - 100%) -- 6.3% chance to OHKO
- -1 252+ Atk Parental Bond Mega Kangaskhan Double-Edge vs. 252 HP / 244+ Def Thundurus: 83-100 (44.6 - 53.7%) -- guaranteed 3HKO after Sitrus Berry recovery

Unown
Useful partners:
- Intimidate: Landorus-T, Incineroar