Banshee (Joint Venture)
Real Name Sean Cassidy
Current Alias Banshee
Alias(es) "Irish," "Shamrock," "Shillelagh", "Patrick", "Red", "Screamer", "Pavarotti"
Relatives Martin Cassidy (father, deceased), Theresa Ryan-Cassidy (mother, deceased), Maeve Rourke (fiance, deceased), Thomas Cassidy (younger brother), Theresa Rourke-Cassidy (daughter)
Affiliation X-Men
Base Of Operations 1407 Graymalkin Lane, Salem Center New York; Cassidy Keep, Ireland
Alignment Good
Universe Joint Venture Universe
Gender Male
Eyes Green
Hair Red
Banshee is a mutant superhero, a veteran of the X-Men and co-founder of Generation X. This is the Joint Venture Universe version of the character.


Early life

Sean Cassidy was born in Cassidy Keep, in Ireland, to a line of wealthy autocrats. Despite the riches and in defiance of idle life he could have had, Sean grew up a thrill-seeker, becoming a biker, daredevil, and general good-natured hell-raiser, as opposed to his quieter, more calculating his younger brother, Tom.

Maeve and Interpol

Wanting to do good in the world, Sean eventually became an agent of the international law enforcement agency Interpol, operating under the code name "Banshee" due to his mutant power to project devastating blasts of sonic energy, which he called his "sonic scream", from his throat.

When his parents tragically died, their estate was split evenly between him and Tom. Neither saw any reason to contest this, since they had grown up nearly inseparable. That closeness was shattered, however, when Sean met a woman named Maeve Rourke on the road near the Keep, and fell in love with her. Tom also cared deeply for her, but never said anything, knowing that she loved Sean, and not wanting to stand in the way of their happiness.

Maeve's death, like their parents', came under violent, mysterious circumstances; and an enraged, grieving Sean opened an investigation with Interpol that led him to America. Tom remained in Ireland, but grew even more resentful of his brother over the following years, as time went on and Maeve's death went unsolved.

Black Tom's Betrayal

Eventually, after Sean returned to Ireland empty-handed again, Tom had had enough. The woman they had both loved was dead, and his brother was failing again and again to find her killer. Angry and embittered, wanting to punish his brother by any means necessary, Tom accepted an exorbitant amount of money to help a team of small-time mutant thieves, vandals, and blackmailers -- Morph, Mastermind, Carmela Unuscione, the Vanisher, and Stonewall -- to enslave Banshee with a special cybernetic suit that overrode his central nervous system, giving their "Mutant Master" complete control over his actions, turning Banshee from an upright enforcer of the law to a common criminal.

Fractures in Factor Six

With Banshee's unwilling aid, the mutant criminals formed Factor Six, and became terrorists at the behest of a mysterious mutant they referred to only as "Master" with varying degrees of investment. Unuscione and Mastermind wholeheartedly supported the Master's quest to bring mutantkind into an era of supremacy, while Morph had doubts and concerns, and Stonewall and Vanisher quickly felt they were getting in over their heads. Sean frequently found himself the unwilling ear in which all of the members of Factor Six whispered their worries and misgivings. Despite himself, he found himself beginning to care about these criminals who he might have before locked away without a second thought, particularly Morph and Stonewall, who seemed to simply wish to live as they pleased, free from the ravages of their mutations or the judgment of humanity.

When Factor Six attacked New York in their first grand-scale wave of terrorism, they ended up in battle against two other mutants, Professor Xavier and Magneto. While they seemed to have the upper hand at first, Xavier and Magneto learned more about Factor Six with every encounter, in large part thanks to Banshee telling them whatever he could when not actively being controlled by one of the other members of the organization.

The outcome of the final confrontation between Factor Six and the two mutant heroes was never truly in doubt; these small-time criminals, despite their array of powers, were outmatched on nearly every level. This was made doubly clear after Stonewall and Vanisher abandoned the team, Morph switched sides to fight alongside the X-Men's founders, and Magneto disabled the Override Suit that was keeping Banshee a slave. Unuscione and Mastermind, the last two "loyal" members of Factor Six, were defeated and incarcerated shortly thereafter.

Xavier Institute: First Class

Partly in gratitude for his freedom, and partly to atone for the acts he was forced to commit, Banshee signed on to help found the Xavier Institute. He assisted Xavier and Magnus in many of their early endeavors, first to help a young girl named Jean Grey cope with her telepathic powers, and then recruit their first official X-Man, Storm, in Cairo. After a battle with the Shadow King for Ororo's soul, the three founders headed back to the British Isles -- specifically, to a genetic research facility on Muir Island, off the coast of Scotland, where Sean fell in love again, this time with the intelligent, strong-willed Scottish geneticist Moira Kinross. Despite only being a stone's-throw away from Cassidy Keep, he never thought to go back, assuming his brother had matters well in hand, not knowing that Tom had a secret he was keeping from Sean: his daughter, Theresa, named for Sean and Tom's late mother.

Today, Banshee serves as a reserve X-Man and the physical fitness instructor and combat trainer for the team. While he has been known to accompany them on missions, he feels his place is at the school teaching, rather than fighting in the field, although there are extenuating circumstances. He enjoys a budding relationship with Moira, and a professional friendliness with Xavier and Magneto, often serving as a mediator for arguments between the two on matters of philosophy and morality. Banshee is part of the glue that holds the Xavier Institute together, his worldly experience and untarnishable idealism making him invaluable to the school, just as much as his powers.


Acoustikinesis: Banshee's mutant power is the ability to create powerful sonic waves with his voice with which he can achieve various effects. It is unknown whether his powers contain a psionic component to them, or are purely physical in nature.

"Sonic Scream": Banshee's primary use of his powers is the ability to generate an incredibly loud and destructive blast of sonic energy with his voice, released in the form of a scream. This blast does not function like normal sound waves -- rather, by adjusting his vocal chords during a scream, Banshee can manipulate the blast in a wide variety of ways.

  • Sonic Beam: The destructive force of his scream travels in a straight beam of concussive force in whatever direction he is screaming. This attack can often cause a sort of 'heat shimmer' in the air, rendering it visible as well as highly audible. People standing near Banshee when he is generating this beam suffer no lasting damage, provided they are not in the beam's path, though most report that their ears ring for a while afterwards.
  • Sonic Cone: Banshee can emit a sonic scream in a conical form as well, with the area of effect growing larger and more intense as the blast travels from his mouth. The maximum range and intensity of this cone of force is unknown.
  • Sonic Blast: In its raw, uncontrolled form, Banshee's sonic scream is an omnidirectional sphere of destructive sonic force, with a potential blast radius of several miles.
  • Sonic Shield: Banshee can use his voice to project a tight web of sound waves around himself or others near him, making a barrier against physical impact.
  • Stunning/Disorienting/Paralysis: Banshee's sonic scream can be potentially devastating to the human body, beyond simply running the risk of deafness. To combat this, he has worked for years on training his vocal chords so that his sonic scream affects living foes in non-lethal ways, such as stunning, disorientation, paralysis, or unconsciousness. He rarely, if ever, uses his sonic scream to kill.

Precise Vocal Control: In addition to his sonic scream, Banshee has complete control of his vocal chords and perfect hearing, which gives him the ability to subtly alter his voice in a variety of ways.

  • Sonar: (Sound Navigation and Ranging). By sending out a precise, pure note and listening to the returning, altered wave-front of the note, Banshee can evaluate his surroundings in total darkness with near-perfect clarity and focus.
  • Vocal Trance: Banshee can change the timbre and quality of his voice to subtly influence people's subconscious, inducing a low-grade form of hypnotic suggestion simply by speaking in the right pitch.
  • Vocal Mimicry: Banshee can exactly duplicate any sound he hears using his vocal chords. In addition, with just a small set of vocal samples, he can perfectly imitate the voice of another person, able to speak his own words in their voice.
  • Perfect Pitch: Banshee has perfect hearing and an excellent sense of pitch, which combine with his vocal control to make him a superlative singer.
  • Sound Immunity: Banshee's hearing and equilibrium are not affected by either his hypersonic abilities or similar sonic-based abilities in others.
  • Superhuman Vocal Stamina: He possesses superhuman stamina in his lungs, throat, and vocal cords, enabling him to sustain his vocal powers for far longer than an average human can scream at the top of their lungs.

Flight: It is unknown precisely how, but Banshee can manipulate sonic waves in such a way as to be able to hover and fly at near-supersonic speeds. It does not appear to be vocally generated, as he is able to speak normally when he does this, but on occasions where Banshee has exhausted his voice, and thereby lost his powers, he also lost the ability to fly in this manner.

Combat/Spy skills: Banshee is a naturally talented detective, and has experience as both an undercover operative, and unarmed combatant, Thanks to his Interpol training, Sean is well-versed in several forms of combat, strategy, and tactics. He is also an excellent marksman with most forms of conventional firearms.


  • Vocal stresses: Sean's vocal cords are susceptible to injury from excessive strain when using his sonic powers, though this stress threshold is far higher than that of the average human. If his throat or vocal chords are damaged in any significant fashion, he will similarly be unable to utilize his sonic scream until the damage heals.
  • Gagging: Banshee's sonic powers only work if he is able to open his mouth -- his body is immune to the effects of his own powers, and thus his own lips and teeth will block a sonic scream. Gagging him, therefore, often serves as a viable way to neutralize these powers.

Former Weaknesses


Banshee's Override Suit, forced upon him by Factor Six.

  • Override Suit: When Black Tom sold Banshee to Factor Six, the organization's mysterious "Mutant Master" outfitted him with a specially-designed costume; a cybernetic suit that allowed the telepath, or indeed anyone with the proper access commands, to obtain complete physical control of Sean Cassidy's body. They could force him to move, fight, and even unleash his sonic scream upon whatever target they chose. He could still think and speak freely when not actively being forced to scream; however, the rest of his body was completely at the mercy of the terrorist organization. This suit was eventually disabled by an electromagnetic pulse from Magneto, allowing Sean full control over his body and powers once more.
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