Banshee
Sean Cassidy
An Irish mutant whose sonic scream can shatter steel, enable flight, and disorient enemies. Sean Cassidy was a seasoned Interpol agent before joining the X-Men, bringing maturity and experience to the team. He later co-founded Generation X with Emma Frost, mentoring the next generation of mutants.
Appearances Over Time
Most Appearances By Series
Generation X (1994) 73 issues
The Uncanny X-Men (1981) 55 issues
The X-Men (1963) 49 issues
Classic X-Men (1986) 44 issues
X-Men (1991) 20 issues
Uncanny X-Men (2019) 13 issues
X-Force (1991) 9 issues
Uncanny X-Men: First Class (2009) 9 issues
X-Men: Legacy (2008) 8 issues
X-Men Unlimited (1993) 8 issues
Event Participation
The X-Men #28
1967
The X-Men #28
January 1967
Sean Cassidy remains a beloved member of the Giant-Size era who never quite got his due after leaving the team early in Claremont's run. Fans consistently call for him to return to a main X-Men roster alongside contemporaries like Sunfire, though the Krakoa era proved particularly cruel to the character. His tenure as headmaster of Generation X and his tragic death cemented his legacy as one of the franchise's most underutilized heroes.