Monferno @ Choice Scarf  
Ability: Blaze  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Flare Blitz  
- Close Combat  
- Endeavor  
- U-turn  

Monferno @ Firium Z  
Ability: Iron Fist  
EVs: 252 Atk / 4 SpD / 252 Spe  
Adamant Nature  
- Swords Dance  
- Flare Blitz  
- Mach Punch  
- Close Combat  

Monferno @ Focus Sash  
Ability: Iron Fist  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Stealth Rock  
- Taunt  
- Endeavor  
- Mach Punch  

Monferno @ Life Orb  
Ability: Blaze  
EVs: 252 SpA / 4 SpD / 252 Spe  
Modest Nature  
IVs: 0 Atk  
- Nasty Plot  
- Vacuum Wave  
- Focus Blast  
- Fire Blast  

Monferno @ Eviolite  
Ability: Iron Fist  
EVs: 252 HP / 144 Def / 36 SpD / 76 Spe  
Careful Nature  
- Taunt  
- Low Kick / Fire Punch
- Will-O-Wisp  
- Slack Off  

Additional Moves: Thunder Punch, Rock Slide
Additional Items: Fightium-Z
Notes: Thunder Punch (and Rock Slide) which was formally used for Swanna still allows you to hit threats like Oricorio-Belle which resisted your STAB options and takes little from U-turn.
All-out-Pummeling gives you a more accurate fighting option for one turn if you are using the special sweeping variant although this is arguably weaker than the physical variant.
The bulky variant functions as a defensive Rotom-Frost check. These Ev's allows it to outpace minimum speed Bulk Up Vigoroth and cripple it with taunt / will-o-wisp while +1 Return will only be able to 3hko you after Stealth Rocks. This also applies for Non-specs Rotom-Frost, with both Sub-Zero Slammer and thunderbolt being a 3hko at best after Stealth Rocks.