Siryn

Theresa Rourke Cassidy is the daughter of Irish X-Man Banshee, inheriting his sonic-based mutant powers — including a devastating sonic scream capable of flight, disorientation, and force blasts. Raised partly in secret, she eventually found her own heroic path through X-Force and X-Factor Investigations.

Siryn burst onto the Bronze Age Marvel scene in Spider-Woman #37 back in 1981, the creation of the legendary Chris Claremont alongside Steve Leialoha and Terry Austin, and she's been a vital thread in the mutant tapestry ever since. A proud member of the X-Men family, she's spent decades sharing adventures with some of Marvel's most compelling characters — Rictor, Tabitha Smith, Sunspot, Roberto Da Costa, and James Proudstar among them — the kind of company that signals she runs in the thick of mutant action. Her deepest roots are sunk into X-Force, X-Factor, and Deadpool, a trio of series that speaks to her range across gritty team books and wilder corners of the Marvel Universe. With 210 catalog appearances, a publishing history stretching all the way to 2025, and six key issues to her name, Siryn is the definition of an enduring fan favorite well worth tracking down.