Siryn (Theresa Maeve Rourke Cassidy) is a superhero appearing in American comic books published by Marvel Comics. Created by writer Chris Claremont and artist Steve Leialoha, the character first appeared in Spider-Woman #37 (April 1981). Theresa Cassidy belongs to a subspecies of humans called mutants, who are born with superhuman abilities. She possesses a sonic voice providing various effects while her name refers to the Sirens of Greek mythology and their hypnotic voices. She is depicted most commonly in association with the X-Men and related teams like X-Factor and X-Force. Theresa Cassidy is the daughter of the superhero Sean Cassidy. The character has also been known as Banshee at various points in her history.
Publication history
1980s–1990s Theresa Cassidy debuted as a villain in Spider-Woman #37 (April 1981), created by writer Chris Claremont and artist Steve Leialoha. She later appeared in Fallen Angels (1987), X-Force (1991), Deadpool: Sins of the Past (1994), and Deadpool (1997).
2000s–2020s Theresa Cassidy appeared in the 2005 Cable and Deadpool series, the 2006 X-Factor, and the 2021 X-Factor series.
In January 2022, Marvel Comics ran a voting contest where voters could pick between one of ten characters to join the X-Men, with Siryn being among the candidates. In July 2022, Siryn appeared in a digital comic released as a companion to the second Hellfire Gala. This comic revealed that the election had also been held in-universe, with Siryn losing the vote.
Fictional character biography
Early life While Sean Cassidy was working on a deep undercover mission for Interpol, his wife Maeve gave birth to their daughter, Theresa, at Cassidy Keep, County Mayo, Ireland. Maeve later dies in an IRA bombing, and with no means to contact Sean, his cousin Tom takes care of Theresa. When Sean returns and learns of his wife's death, he is devastated. Before Tom can tell him about Theresa, Sean lashes out at Tom with his sonic scream for not having taken better care of Maeve. As Sean flies away in anger, Tom falls into a chasm and breaks his leg, leaving him with a limp. Tom swears to make Sean pay and vows to never tell him about his daughter, and raises her himself.X-Force (vol. 1) #31 Marvel Comics.
Tom (now known as Black Tom) trains Theresa as his apprentice in his criminal activities. As a young teen, she accompanies him and his then-partner, the Juggernaut, to San Francisco. She takes the name Siryn, aids them in a vibranium theft, and battles the original Spider-Woman.Spider-Woman #37. Marvel Comics. Due to her inexperience, she performs poorly in battle and is defeated by Spider-Woman again during Black Tom's temporary capture. Initially believing her to be seriously hurt, Black Tom resolves to break all association with her so that she will not be exposed to further danger. While in custody, he absolves Theresa of all responsibility for her crimes,Spider-Woman #38 Marvel Comics. and writes a letter to Sean explaining who she is. The X-Men bring Theresa back to their headquarters, where she is joyfully reunited with her father.Claremont, Chris. Uncanny X-Men #148 Marvel Comics.
Muir Island
Theresa moves to Muir Island, home of the research laboratories of Moira MacTaggert, a longtime ally of Professor Xavier. During an overnight visit to Xavier Institute, Siryn, Kitty Pryde, Illyana Rasputin, and a young Muir Island resident named Amp battle robotic duplicates of the Brotherhood of Evil Mutants after accidentally releasing them from the Danger Room. Later in the evening, Siryn gets into a fist fight with Kitty after Amp convinces her that Kitty was trying to sabotage her chances with a young man named Dimitri. After the fight is broken up by Wolverine, the girls reconcile and leave on friendly terms.Van Lente, Fred. Wolverine: First Class #6 Marvel Comics. She also accompanies Wolverine and Kitty when they are asked by Professor Xavier to act as bodyguards for the mutant pop-star Dazzler. Dazzler is impressed with Theresa's rendition of "Amazing Grace" and asks her to act as a backing vocalist for her concert.David, Peter (w). Wolverine: First Class #16. Marvel Comics.
On the island, Siryn starts a romantic relationship with Jamie Madrox. This version of Multiple Man is revealed to be one of his many duplicates and not the original Multiple Man, leading to the end of the relationship. During this time Siryn and Multiple Man travel to New York City.Fallen Angels #1 Marvel Comics. She and Madrox search for two members of the New Mutants: Sunspot and Warlock, who had run away from the school.Fallen Angels #2 Marvel Comics. Siryn and Multiple Man find Sunspot and meet the association of street-level mutants known as the Fallen Angels,Fallen Angels #3 Marvel Comics. and they are all transported to Devil Dinosaur's planet.Fallen Angels #4. Marvel Comics. They travel to the Coconut Grove, the home planet of the alien Ariel.Fallen Angels #6. Marvel Comics. While there, her superhuman powers are neutralized and she is made a captive by Unipar.Fallen Angels #7. Marvel Comics. She regains her superhuman powers and returns to Earth. She chooses to remain in the Fallen Angels for some time to help reform their criminal members.Fallen Angels #8. Marvel Comics.
Back on Muir Island, she briefly falls under the mental control of the Shadow King.Claremont, Chris. Uncanny X-Men #278 Marvel Comics.Claremont, Chris. Uncanny X-Men #280. Marvel Comics.
X-Force
Siryn becomes a core member of X-Force, a paramilitary superhero team and for a time was its field leader. As a member of X-Force, her teammate Warpath develops a romantic interest in her while she begins flirting with Deadpool. Deadpool and Siryn become involved when the two fight Black Tom Cassidy and Juggernaut. Although Banshee warns Siryn that Deadpool is a madman and a murderer, she finds Deadpool attractive, and the feelings are reciprocated. Over time, Siryn becomes the voice of reason and sanity in Deadpool's ear. She assists him in some of his missions, such as when Deadpool felt he needed blood from the Hulk to cure problems with his own healing powers.Deadpool Vol. 3 #4 In the end Siryn becomes overwhelmed with balancing her duties with X-Force and the demands of Deadpool's mental health. She promises him that she would consider progressing their relationship if he continues on the path of good, and once she has her X-Force responsibilities secured. Warpath continues to seek Siryn's affections, and makes his dislike for Deadpool clear during a visit to the baseball diamond used in Field of Dreams.Deadpool (vol. 3) #12. Marvel Comics.
Siryn confronts various adversaries during her time in X-Force: she puts down a coup in Asgard, and confronts Onslaught, Mojo, and S.H.I.E.L.D. on more than one occasion. Warpath helps her cope with her drinking problems, eventually leading her to become sober.
She becomes a vital part of the team, as opined by an aspect of Charles Xavier,X-Force (vol. 1) #68. Marvel Comics. which saves the entire team from a near-death experience.
She leaves when Feral, a former teammate turned villain, slashes her throat, destroying her vocal cords and rendering her temporarily mute and powerless.X-Force (vol. 1) #90 (May 1999). Marvel Comics.
X-Corporation Deadpool tracks down Wolverine and steals a sample of his bloodWolverine #154 - #155 (Sept, Oct 2000), Marvel Comics. to heal Siryn, who regains the use of her vocal cords.
Siryn joins the Paris branch of X-Corporation, claiming to atone for her father's sins for his failed X-Corps idea, where she reunites with Multiple Man, Rictor and Cannonball. She works with Monet St. Croix for the first time.New X-Men (vol. 1) #128, Marvel Comics. Their first mission does not go well and Siryn deals with the loss of her teammate, Darkstar.New X-Men (vol. 1) #130 (Oct 2002), Marvel Comics.
X-Factor Investigations Siryn leaves X-Corporation to become a member of X-Factor Investigations. As part of her initial duties for X-Factor Investigations, she investigates the murder of a woman who died in a movie star's penthouse, on behalf of the victim's sister. A rival firm, Singularity Investigations, represents the actor with Damian Tryp as the defense counsel. Siryn and X-Factor Investigations manage to incriminate the star and thwart Singularity Investigation's assassination attempt on Rictor.David, Peter (w). X-Factor (vol. 3) #8-9 (March - April 2006). Marvel Comics. Tryp later ambushes Siryn and beats her, leaving her to die in an alley. She is later found and taken hostage by a mentally ill former mutant only to be rescued by Rictor.David, Peter (w). X-Factor (vol. 3) #5. Marvel Comics.
While recovering from her injuries, Cyclops approaches Theresa and informs her Banshee has died. She goes into a state of denial, holding on to how many X-Men have been believed dead have returned alive.David, Peter (w). X-Factor (vol. 3) 7. Marvel Comics.
During "Civil War", Theresa opposes the registration act and is tasked with contacting more high-profile superheroes about the Decimation. After speaking with Spider-Man, X-Factor gets into contact with Quicksilver and Cyclops' team of X-Men, demanding they answer why the reason behind the Decimation was kept secret and defy the registration act.David, Peter (w). X-Factor (vol. 3) #8-9. Marvel Comics.
Siryn's relationships with Multiple Man and Monet become strained. After spending a night drinking, Madrox awakens to learn that he and one of his duplicates slept with Theresa and Monet.David, Peter. X-Factor #10 Marvel Comics. (October 2006) Although he is initially uncertain as to which was which,David, Peter (w). X-Factor #13 (January 2007). Marvel Comics. he concludes with near certainty that he slept with Theresa, and the dupe slept with Monet, though this does little to assuage Theresa and Monet's anger.David, Peter (w). X-Factor #14 Marvel Comics. (February 2007) Theresa resolves her differences with both Madrox and Monet, and the two women develop a budding friendship after a shopping trip to Paris and partner together on later missions.David, Peter (w). X-Factor (vol. 3) #15. Marvel Comics.
Siryn and Monet are sent to retrieve two famous child singers (who specialize in mutant hate songs) from their parents. The two are ambushed, knocked out, and kidnapped by the children's mutant bodyguards, Solo and Clay. They awake imprisoned,David, Peter (w). X-Factor (vol. 3) #22. Marvel Comics. but they both escape and return the children to their grandparents. It is revealed that the entire mission was a ruse by Josef Huber to lure the women away from their X-Factor teammates, as both Monet and Siryn's mental-based powers negatively affect Huber's mind-control abilities.David, Peter (w). X-Factor (vol. 3) #21-24. Marvel Comics.
Messiah Complex Theresa assists Rictor's infiltration of the Purifiers and accompanies the X-Men to rescue the mutant baby and X-Force. She later receives a call from Peepers, who is being pursued by Predator X, but Theresa arrives too late to help him and finds his remains.David, Peter (w). X-Factor (vol. 2) #26 (2008). Marvel Comics. Siryn prays at Madrox's bedside when he awakes, and takes part in the X-Men's assault on the Marauders' base with Monet and Strong Guy, fighting Exodus in the battle.David, Peter (w). X-Factor (vol. 2) #27 (2008). Marvel Comics.
Divided We Stand Siryn reveals that she is pregnant with Jamie's child, and after talking with Monet reveals she intends to keep it. When she attempts to tell Jamie he mistakenly believes that she wants to quit X-Factor. Monet later helps Siryn realize that she still loves Jamie. Siryn tries to tell him again, but Arcade appears and destroys Mutant Town. Afterwards, Jamie reveals he knows she is pregnant and the team moves to Detroit, Michigan, to get away from Valerie Cooper and the Office of National Emergency (O*N*E).David, Peter (w). X-Factor (vol. 3) #28-32. Marvel Comics.
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