Siryn
Theresa Cassidy

Powers

• Disruption: Amazing damage to unliving targets Incredible to living targets, Remarkable stunning to entire area.
• Flight: Typical
• Sonar: Amazing
• Sonic Creatures: Siryn can create illusionary creatures of living sound with max stats of Excellent.
• Sonic Shield: Amazing

Talents

Leadership

Contacts

Xmen, Banshee, Xforce

History

Theresa Rourke is the mutant daughter of Sean Cassidy, the mutant now known as the Banshee, and Maeve Rourke. At the time of his marriage, Sean Cassidy worked as an Interpol agent, and not long after was sent on an undercover anti-terrorist mission which kept him out of touch with his family for about a year and a half. Neither Sean nor Maeve knew at the time he left that she was pregnant. Maeve remained at Cassidy Keep, the family castle, during her pregnancy and the time immediately following Theresa's birth and so relatively few people knew of Theresa's existence. Sometime later Maeve was killed in an IRA bombing along with a number of other people. Those who knew of Theresa's existence assumed that she too had been killed in the explosion, which had left the corpses of its many victims unrecognizable, and decided not to tell Sean Cassidy that Maeve had had a daughter in order to spare him additional grief.

Unknown to Sean, the baby Theresa had been found after the explosion by his cousin Black Tom Cassidy, who, suspecting that she might be a superhumanly powerful mutant as he and her father were, decided to raise her secretly himself. Theresa's sonic powers, inherited from her father, emerged at puberty, and a few years afterwards Black Tom began enlisting her aid in committing crimes. However, Theresa's heart was never in a life of crime, and she pursued it only because the man who raised her, Black Tom, ordered her to do so.

Eventually, Theresa accompanied Black Tom and his partner, the Juggernaut, to San Francisco to assist him in crimes. Here, employing the name Siryn, she battled the original Spider-Woman and several of the X-Men. This conflict ended in Black Tom's temporary capture. While in custody, Black Tom exonerated Theresa of responsibility for her crimes and wrote a letter to Sean explaining who she was. The X-Men brought Theresa back to their headquarters, where she was joyfully reunited with her father.

For a time Siryn joined the Fallen Angels, a band of young superhumans, hoping to keep them out of trouble. Later, she lived for a while at Moira MacTaggert's Mutant Research Centre at Muir Island. She eventually came to join X-Force, the mutant strike team organized by Cable. As a testament to her skills, Theresa was made the deputy leader of X-Force after Cannonball graduated to the X-Men. Recently she has become romantically involved with the masked mercenary Deadpool.