Siryn 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. 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. Theresa Cassidy is the daughter of the superhero Sean Cassidy. The character has also been known as Siryn and Banshee at various points in her history.
Theresa Cassidy / Siryn. Art by Ryan Sook.
X-Force #90 in which Feral injures Siryn.
Christopher S. Claremont is an American comic book writer and novelist, known for his 16-year stint on Uncanny X-Men from 1975 to 1991, far longer than that of any other writer, during which he is credited with developing strong female characters as well as introducing complex literary themes into superhero narratives, turning the once underachieving comic into one of Marvel's most popular series.
Claremont at the 2016 New York Comic Con
Claremont being interviewed on breaking into the comics industry at the 2011 New York Comic Con
Claremont at the Comic New York symposium at Columbia University on March 24, 2012