Real Name: St. John Allerdyce
Previous Affiliations: Student, Xavier Institute
Powers & History: John Allerdyce is a pyrokinetic, who can manipulate fire and make it do what he wants. Since he cannot generate the fire himself, he usually uses a Zippo lighter, but can even use such small flames as those inside a lighted cigarette.
When Rogue first came to the Institute, John showed off by creating a ball of fire he balanced on his hand until his friend Bobby froze it solid [Refer X-Men (2000)].
John, Bobby and Rogue became fairly close friends, with a "fire and ice" rivalry existing between the boys. John's literal hot-headeness got him into trouble with Professor X when he made a human teen's cigarette explode in a public museum.
John was further disillusioned with humanity and the X-Men's credo after Bobby's brother called the police on them. Rather than submit to arrest, he attacked the Boston police with giant fireballs, blowing up a few squad cars. This resentment led John to leave the X-Jet and join Magneto and Mystique as they leave Alkali Lake in a Chinook helicopter.
Taking the name "Pyro," John apparently has chosen the life of a terrorist.
Pyro in X2: X-Men United (2003)
Pyro in X-Men 3 (2006)