Editing Siryn (section)

==Publication history==

=== 1980s–1990s ===
Theresa Cassidy debuted as a villain in ''[[Spider-Woman (Jessica Drew)|Spider-Woman]]'' #37 (April 1981), created by writer [[Chris Claremont]] and artist [[Steve Leialoha]].<ref>{{cite book |last1=DeFalco |first1=Tom |title=The Marvel Encyclopedia |last2=Sanderson |first2=Peter |last3=Brevoort |first3=Tom |last4=Teitelbaum |first4=Michael |last5=Wallace |first5=Daniel |last6=Darling |first6=Andrew |last7=Forbeck |first7=Matt |last8=Cowsill |first8=Alan |last9=Bray |first9=Adam |date=2019 |publisher=DK Publishing |isbn=978-1-4654-7890-0 |page=335}}</ref> She later appeared in the 1987 ''[[Fallen Angels (comics)|Fallen Angels]]'' series.<ref>{{Cite web |last=Marnell |first=Blair |date=March 17, 2019 |title=A St. Patrick's Day Salute to Siryn |url=https://www.marvel.com/articles/comics/a-st-patrick-s-day-salute-to-siryn |access-date=May 20, 2023 |website=[[Marvel.com]]}}</ref><ref>{{Cite web |last=Derman |first=Matt |date=August 14, 2014 |title=1987 And All That: Fallen Angels #1-8 |url=https://www.cbr.com/1987-and-all-that-fallen-angels-1-8/ |access-date=May 20, 2023 |website=[[Comic Book Resources]] |language=en}}</ref> She appeared in the 1991 ''[[X-Force]]'' series. She appeared in the 1994 ''Deadpool: Sins of the Past'' series.<ref>{{Cite web |last=Hill |first=Brad |date=May 29, 2022 |title=From 'Dead Presidents' to '5 Ronins': 9 best Deadpool comics that every fan should read |url=https://www.sportskeeda.com/comics/9-best-deadpool-comics-every-fan-read |access-date=May 20, 2023 |website=[[Sportskeeda]] |language=en-us}}</ref><ref>{{Cite web |last=Jasper |first=Gavin |date=May 24, 2018 |title=Deadpool Reading Order: Get to Know The Merc With a Mouth |url=https://www.denofgeek.com/comics/deadpool-reading-order-get-to-know-the-merc-with-a-mouth/ |access-date=May 20, 2023 |website=[[Den of Geek]] |language=en-US}}</ref> She appeared in the 1997 ''Deadpool'' series.

=== 2000s–2020s ===
Theresa Cassidy appeared in the 2005 ''[[Cable and Deadpool]]'' series. She later appeared in the 2006 ''[[X-Factor (comics)|X-Factor]]'' series. She appeared in the 2021 ''X-Factor'' series.<ref>{{Cite web |last=Terror |first=Jude |date=January 11, 2021 |title=In This Issue, a Character Will DIE! - X-Factor #6 [XH] |url=https://bleedingcool.com/comics/in-this-issue-a-character-will-die-x-factor-6-xh/ |access-date=May 20, 2023 |website=[[Bleeding Cool]] |language=en}}</ref><ref>{{Cite web |author1=Arrant |first=Chris |date=May 6, 2021 |title=A dark side to X-Men Founders' party revealed in X-Factor #9 preview |url=https://www.gamesradar.com/a-dark-side-to-x-men-founders-party-revealed-in-x-factor-9-preview/ |access-date=May 20, 2023 |website=[[Newsarama]] |language=en}}</ref>