Banshee

Real Name: Sean Cassidy

Powers: Depending on the intensity of the sound, Banshee's sonic scream can shatter objects, enable him to fly or induce unconsciousness in others.

History: Sean Cassidy -- born heir to the castle and estate of Cassidy Keep, Ireland -- manifested his mutant abilities as an adolescent, but kept them hidden. After graduating from Trinity College in Dublin, he went to work for the international law-enforcement agency known as Interpol. While Cassidy was out of touch on a top-secret assignment, his wife discovered that she was pregnant and gave birth to their daughter. Maeve Cassidy took the infant to visit relatives in Northern Ireland, where she was killed in a terrorist explosion. Authorities found no trace of baby Theresa, whom they assumed also had died. Cassidy was not told of his daughter's birth to spare him further heartache.

Grief-stricken, he left Interpol to become a freelance operative, but eventually found himself engaged in criminal activities. Valuable for his mutant powers and insider's knowledge of the law-enforcement community, Cassidy was coerced to obey the subversive organization known as Factor Three with a headband containing explosives. During his time with Factor Three, Cassidy gained the codename Banshee and clashed with the X-Men, an outlaw band of heroic mutant adventurers. The telepathic, telekinetic Charles Xavier subsequently disabled the detonation mechanism in Cassidy's headband, freeing him from indentured servitude to Factor Three.

Banshee returned to an honest life, fighting alongside the X-Men for a time before retiring. Subsequently, Xavier's charges battled Banshee's cousin, the mutant terrorist called Black Tom Cassidy. Joining the fray was Siryn -- Banshee's daughter, Theresa, rescued by Black Tom from the explosion that had killed her mother. After the X-Men defeated the duo, Banshee and Theresa came together at Xavier's mansion for a joyful reunion. Later, Banshee became co-headmaster at the Massachusetts Academy, teaching the young mutants of Generation X to control their strange powers ... and cope with their condition as mutant outcasts, hated and feared by humanity.