NFE All-Out Attacker (Magmar) @ Choice Specs / Life Orb  
Ability: Vital Spirit  
EVs: 252 SpA / 4 SpD / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Fire Blast  
- Psychic  
- Focus Blast  
- Hidden Power [Grass]
NFE Belly Drum (Magmar) @ Normalium Z  
Ability: Flame Body  
EVs: 252 Atk / 4 SpD / 252 Spe  
Adamant Nature  
- Belly Drum  
- Fire Punch  
- Thunder Punch  
- Mach Punch
Optional Move(s): 
- Substitute
Optional Item(s): 
- Aquav Berry
- Choice Scarf
- Eviolite
- Firium Z
- Psychium Z
Optional Ability: 
- N/A
Optional EV/IV(s):  
- 252 SpA / 4 SpD / 252 Spe (Modest)
Overview: With good coverage options and a good Speed and Special Attack stat, both Choice Specs and Life Orb Magmar act as good wallbreakers in the current metagame. It is also a versatile Pokemon, since it can also viably run a fearsome Belly Drum sweeper set. It faces competition as a Fire-type wallbreaker from Monferno and Combusken, which slightly limits its viability.
All-Out Attacker: Choice Specs / Life Orb Fire Blast hits Grass- and Steel-types such as Roselia, Servine, Gloom, Ferroseed, and Metang for super effective damage, while hitting most neutral targets reasonably hard. Psychic hits Fighting-types such as Machoke and Hakamo-o harder than Fire Blast but it also hits Mareanie hard. Focus Blast is a good coverage move for Normal-types such as Munchlax. Hidden Power Grass is primarily for Marshtomp but also hits other bulky Water-types such as Prinplup and Wartortle for super effective damage. 
Belly Drum: This set can act as both an early-game wallbreaker or late-game wincon which takes advantage of any switches forced by the special Magmar set. Fire Punch OHKOs neutral and super effective targets at +6 Attack. Thunder Punch hits bulky Flying- and Water-types such as Mareanie, Staravia, Prinplup, and Wartortle hard. Mach Punch picks off weakened frailer threats at +6 Attack such as Frogadier and Electabuzz.
Checks and Counters: Sliggoo walls special Magmar; it easily tanks any hit and threatens Magmar out. Bulky Water-types such as Prinplup and Wartortle can typically withstand a hit or two from Magmar and force it out. Choice Specs Magmar is reliant on good prediction to effectively break against teams with a sturdy fire resist and Life Orb Magmar is very susceptible to chip from Life Orb recoil and hazards. For example, specially defensive Mareanie does not appreciate switching into Psychic but can effectively pivot around Choice Specs Magmar unless it is played perfectly. Magmar has good speed for a frail wallbreaker, but faster offensive threats such as Electabuzz, Frogadier, Haunter, and Kadabra can typically revenge kill it at full or after minimal chip. Belly Drum Magmar is much harder to wall once setup but it is frail and easy to revenge kill before it sets up.