Rotom-Frost @ Choice Scarf / Choice Specs
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Blizzard
- Volt Switch
- Thunderbolt
- Trick

Rotom-Frost @ Icium Z
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Blizzard
- Volt Switch
- Thunderbolt
- Pain Split / Substitute

Rotom-Frost @ Damp Rock / Icium Z / Electrium Z / Waterium Z
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Blizzard
- Volt Switch
- Thunder
- Rain Dance

Additional move options: Defog, Will-O-Wisp, Substitute
Additional item options: Leftovers, Safety Goggles
Notes: The Rain Dance set should only ever be used on full rain teams. 
Sets such as SubSplit are functional, but the best performing Frost sets are generally Choice Scarf and Icium Z.