Deadpool wins.
This isn't even a question.
Deadpool, an insane healing factor, cursed by death not to be ale to die, expert assassin with inhanced reflexes/speed/agility/strength.
Plus, a quick and insane temper with no remorse for beating your ass to death(see typhoid mary)
Versus
Pyro, a man who can control fire and shoot it at you.
Deadpool.
Actual, this wouldn't happen for three reasons.
1. deadpool is both immortal, ut also, insane healing factor that would heal the wounds as quick as he got them.
2. he is as fast as wolverine and an expert fighter so he knows how to get to pyro and is quick enough to get to him and kill him.
3. Deadpool is a ****in' physco, alittle fire isn't gonna stop him, even if he gets burnt lunging through the firewall, pyro dies.
Face it.
Deadpool wins.
I'm pretty confident in Deadpool to win this. After all, when it comes down to it, Pyro is just a man. A normal, every day human. By this, I am referring to his speed, agility, fighting ability.
Deadpool could do this without weapons, and with one hand tied behind his back. Quite literally. Deadpool has the speed and agility to dodge fireballs, and even if he had to walk through a wall of fire, he could heal from it, no problem. At which point, Deadpool could procede to snap Pyro's neck with two fingers, as he has exhibited the ability to do.
This isn't really even close.