Bulky Attacker Heatran
[email protected] Air Balloon
Ability: Flash Fire
EVs (if you care): 252 SpA / 252 HP / 4 SDef
- Fire Blast
- Earth Power
For the final pair of attacks, I recommend Earth Power and Protect. Earth Power is used to hit Magnezone, Fire-types who threaten your team, and opposing Heatran (WARNING: This set is completely walled by opposing Air Balloon Heatran). Since you have Toxic, I assume that you are going to be Toxic stalling, which requires Protect.
Honourable Mentions: Flash Cannon can be used to check Fairies and Ice-types who threaten your Dragons. Lava Plume can be used in the place of Fire Blast for more accuracy and a 30% chance to burn. You could also run Solar Beam if this is for use on a Sun team. Stealth Rock works well for the lead role, and screws over opposing Talonflame and Mega Charizard Y.
I hope that this will be of use to you in future battles, and good luck!