Can't help you there, I'm afraid. The mechanics of the canon setting are not exactly my specialty. I recommend taking a look at the custom power thread, which might have something helpful for such a character.
In any case, this isn't really the place for that discussion. A new thread would probably be a good idea.
The following writeup is based entirely upon my incomplete understanding of firefighting.
Firefighter (On the Beach)
High Concept: Firefighter
Other Aspects: The Real Heroes, Dangerous Job
Skills:
Good: Endurance
Fair: Might, Scholarship, Weapons, Athletics
Average: Alertness, Driving, Conviction, Investigation
Stunts:
Toughness Of Mind And Body (Endurance): Use Endurance to defend against fear.
Fireproof (Endurance): Armour 2 against fire.
First Aid (Scholarship): +2 to apply emergency medical aid.
Fire Truck (Driving): +2 to drive a fire truck.
I Know My Job (Alertness): +2 to assessments and declarations related to his job.
Total Refresh Cost:
-3 (Pure Mortal)
Refresh Total:
1