The Birth of His and Siryn's Child Should Have Been a Celebration, Not a Tragedy In Peter David's X-Factor #39 from 2009, Jamie Madrox and his teammate Theresa Cassidy, the daughter of classic X ...

Siryn, whose real name is Theresa Cassidy, is the daughter of Sean Cassidy, better known as longtime X-Man Banshee. As you can see in the image below, Siryn has a green and yellow costume with a ...