Rotom-Wash @ Sitrus Berry  
Ability: Levitate  
Level: 50  
EVs: 252 HP / 108 Def / 12 SpA / 116 SpD / 20 Spe  
Bold Nature  
IVs: 0 Atk  
- Thunderbolt  
- Protect  
- Hydro Pump  
- Electroweb

Unown
Options:
- supportive: Will-O-Wisp, Light Screen, Volt Switch, Ally Switch
- items: Waterium Z, Safety Goggles, Wiki Berry

Unown
Offensive calcs:
- 12 SpA Rotom-W Thunderbolt vs. 252 HP / 4 SpD Mega Slowking: 102-120 (50.4 - 59.4%) -- guaranteed 2HKO
- 12 SpA Rotom-W Hydro Pump vs. 252 HP / 4 SpD Mega Dhelmise in Heavy Rain: 88-105 (49.7 - 59.3%) -- 99.6% chance to 2HKO
Defensive calcs:
- 252+ SpA Aegislash-Blade Never-Ending Nightmare (160 BP) vs. 252 HP / 116 SpD Rotom-W: 135-159 (85.9 - 101.2%) -- 6.3% chance to OHKO
- 252 SpA Transistor Regieleki Thunderbolt vs. 252 HP / 116 SpD Rotom-W: 82-97 (52.2 - 61.7%) -- guaranteed 3HKO after Sitrus Berry recovery
- 252+ SpA Walrein Freeze-Dry vs. 252 HP / 116 SpD Rotom-W: 120-144 (76.4 - 91.7%) -- guaranteed 2HKO after Sitrus Berry recovery
- 4 Atk Kartana Leaf Blade vs. 252 HP / 108+ Def Rotom-W: 134-158 (85.3 - 100.6%) -- 6.3% chance to OHKO
- 252+ Atk Huge Power Mega Mawile Play Rough vs. 252 HP / 108+ Def Rotom-W: 127-151 (80.8 - 96.1%) -- guaranteed 2HKO after Sitrus Berry recovery
- 252+ Atk Life Orb Arctozolt Bolt Beak (170 BP) vs. 252 HP / 108+ Def Rotom-W: 134-160 (85.3 - 101.9%) -- 12.5% chance to OHKO
- 252 Atk Urshifu-Rapid Strike Close Combat vs. 252 HP / 108+ Def Rotom-W: 79-94 (50.3 - 59.8%) -- guaranteed 3HKO after Sitrus Berry recovery

Rotom-Wash @ Waterium Z  
Ability: Levitate  
Level: 50  
EVs: 252 HP / 140 SpA / 116 SpD  
Modest Nature  
IVs: 0 Atk  
- Thunderbolt  
- Nasty Plot  
- Hydro Pump  
- Protect

Unown
Offensive calcs:
- 140+ SpA Rotom-W Hydro Vortex (185 BP) vs. 252 HP / 4 SpD Mega Dhelmise in Heavy Rain: 180-213 (101.6 - 120.3%) -- guaranteed OHKO
- 140+ SpA Rotom-W Hydro Vortex (185 BP) vs. 236 HP / 236+ SpD Incineroar: 212-252 (106 - 126%) -- guaranteed OHKO
- 140+ SpA Rotom-W Hydro Pump vs. 4 HP / 0 SpD Landorus-T: 194-230 (117.5 - 139.3%) -- guaranteed OHKO
- +2 140+ SpA Rotom-W Thunderbolt vs. 252 HP / 72+ SpD Mega Slowking: 210-248 (103.9 - 122.7%) -- guaranteed OHKO
- +2 140+ SpA Rotom-W Hydro Pump vs. 4 HP / 0 SpD Tapu Lele: 144-171 (98.6 - 117.1%) -- 93.8% chance to OHKO
- +2 140+ SpA Rotom-W Hydro Vortex vs. 252 HP / 4 SpD Glastrier: 250-295 (120.7 - 142.5%) -- guaranteed OHKO
Defensive calcs:
- 252+ SpA Aegislash-Blade Never-Ending Nightmare (160 BP) vs. 252 HP / 116 SpD Rotom-W: 135-159 (85.9 - 101.2%) -- 6.3% chance to OHKO
- 252+ Atk Parental Bond Mega Kangaskhan Double-Edge vs. 252 HP / 0 Def Rotom-W: 130-156 (82.8 - 99.3%) -- guaranteed 2HKO
- 252+ SpA Mega Walrein Freeze-Dry vs. 252 HP / 116 SpD Rotom-W: 120-144 (76.4 - 91.7%) -- guaranteed 2HKO