Who is the Pyro?

Interview with Soldier

Soldier: "When rockets, bombs, and bullets won't work, cry 'Havoc' and let slip the dogs of fire,". Sun Tzu said that.
Mr. Deep: ...Ok... Anyway, Soldier, do you remember what your initial thoughts were when Pyro joined your squadron?
Soldier: During the early fights of the Great Gravel Wars, it was only me, Heavy and Engi. I called that yelling lady, demanding more American troops; what I got was Pyro.
Mr. Deep: You don't think Pyro is from the United States?
Soldier: OF COURSE SHE'S NOT! No self respecting patriot would need to wear a gas mask at all times. A true soldier would show his blood-stained, battle scarred face off to the world, to show his enemies just how much they have to fear. They are not scarred of mumbling maggots. AND I SHOULD KNOW!
Mr. Deep: You conducted a survey with the BLU Mercs?
Soldier: No. I sent them a letter telling them not to attack my control point. They replied with a drawing of Pyro's mask drawn in blood.
Mr. Deep: I...don't know what that signifies, but I'll take your word for it.
Soldier: I also think that Pyro is not even a man!
Mr. Deep: You think Pyro is a woman?
Soldier: She giggles, maggot. No man worth his testicles would giggle on my battlefield.
Mr. Deep: O...k...
Soldier: But if I am being honest in this interview. Pyro is a good soldier. She follows my orders without hesitation and laughs at the face of danger. She is the only maggot I never have to yell at for failure. So despite her...flaws...I am proud to have Pyro on my team.
Mr. Deep: Wow, Soldier. Never pegged you for the inspirational sort.
Soldier: I have read War and Peace.
Mr. Deep: You read anything with the word "war" in it, don't you?
Soldier: Affirmative.