Idk if we're allowed to use the same Pokemon, so just ignore me if we aren't :P
Air Balloon Heatran as a
Counter
Heatran @ Air Balloon
Ability: Flash Fire
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Fire Blast
- Earth Power
- Flash Cannon
- Stealth Rock / Stone Edge
So long as your Heatran doesn't get its balloon popped, you can switch this in without fear every single time. Stallbreaker Heatran literally can't touch it, while you can OHKO in return with Earth Power. It still beats opposing Air Balloon variants, since you can just pop their balloon with a Flash Cannon, while they have no means of popping yours.
252 SpA Heatran Earth Power vs. 0 HP / 4 SpD Heatran: 372-440 (115.1 - 136.2%) -- guaranteed OHKO
Heatran Magma Storm vs. Flash Fire Heatran: 0-0 (0 - 0%) -- aim for the horn next time
Heatran Earth Power vs. Air Balloon Heatran: 0-0 (0 - 0%) -- aim for the horn next time
252 SpA Heatran Solar Beam vs. 0 HP / 0 SpD Heatran: 31-36 (9.5 - 11.1%) -- possible 9HKO