Magearna @ Fightinium Z  
Ability: Soul-Heart  
EVs: 252 HP / 252 SpA / 4 SpD  
Modest Nature  
IVs: 0 Atk  
- Calm Mind  
- Iron Defense  
- Pain Split  
- Aura Sphere  

Heatran @ Choice Scarf  
Ability: Flash Fire  
EVs: 4 HP / 252 SpA / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Overheat  
- Hyper Beam  
- Hidden Power [Fighting]  
- Earth Power  

Lucario-Mega @ Lucarionite  
Ability: Adaptability  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Bone Rush  
- Close Combat  
- Swords Dance  
- Magnet Rise  

don't know much about steel but:
lucario beats all the mons that rely on eq and most slower steels including non scarf heatran, excadrill, steelix, magnezone (if 3 hits with bone rush)
heatran ohko's most of the tier and mainly loses to faster scarfers
magearna lives some shit and can beat steela