X–Men Explorer v.02
Siryn

Siryn

Theresa Maeve Rourke Cassidy

Created by Steve Englehart & Jim Mooney
First Appearance
Spider-Woman #37 (1981)
Appearances
325
Primary Team
X-Force
Debut Era
1980s

Daughter of Banshee, Siryn inherited her father's sonic scream and eventually his codename. A natural leader who co-led X-Force and later anchored X-Factor Investigations, she struggled with alcoholism and her father's death with a rawness unusual for superhero comics. Later became the Morrigan, an Irish death goddess.

Appearances Over Time

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Series

Most Appearances By Series

X-Force (1991) 106 issues

Issues #10 – #99

106 of 130 issues (82%)

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X-Factor (2006) 96 issues

Issues #1 – #9

96 of 114 issues (84%)

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Deadpool (1997) 13 issues

Issues #12 – #69

13 of 70 issues (19%)

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X-Factor (2006) 10 issues

Issues #10 – #9

10 of 1 issues (1000%)

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The Uncanny X-Men (1981) 8 issues

Issues #148 – #542

8 of 405 issues (2%)

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Fallen Angels (1987) 8 issues

Issues #1 – #8

8 of 8 issues (100%)

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Cable (1993) 7 issues

Issues #14 – #8

7 of 108 issues (6%)

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New X-Men (2001) 6 issues

Issues #128 – #131

6 of 43 issues (14%)

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X-Man (1995) 6 issues

Issues #1 – #54

6 of 76 issues (8%)

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X-Factor (2020) 5 issues

Issues #4 – #9

5 of 10 issues (50%)

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Events

Event Participation

First Appearance

Spider-Woman #37

1981

First X-Men Appearance

X-Force #3

October 1991

Fan Sentiment

Siryn remains a beloved legacy character who brought heart and depth to X-Force and X-Factor, particularly during Peter David's acclaimed runs. Her tumultuous relationship with Deadpool and her role as Banshee's daughter gave her emotional weight that resonated with readers. While she's frequently mentioned in discussions about underutilized X-Women who deserve more spotlight in adaptations, her contributions to team dynamics (especially in X-Factor's detective agency era) are consistently praised.

Real Name

Theresa Maeve Rourke Cassidy

Teams
Created By

Steve Englehart & Jim Mooney