Known Relatives: Barry Allen (father), Iris Allen (mother)
Relatives (Don): Meloni Thawne (wife), Bart Allen (son)
Relatives (Dawn): Jeven Ognats (husband), Jenni Ognats (daughter)
Base of Operations: 30th Century (born 2958 *)
Death: Killed by Dominion agents in 2980 *
First Appearance: Adventure Comics #373 (October 1968)**
Born in the 30th Century to Iris West Allen, twin brother and sister Don and Dawn inherited partial super-speed from their father, Barry Allen, the second Flash. They grew up in an era of xenophobia in which metahumans were as unwelcome as aliens, so for a long time they had to operate in secret, appearing only as tornadoes.
Dawn married Jeven Ognats of Aarok, and their daughter Jenni later joined the Legion of Superheroes.
Don’s marriage to Meloni Thawne, however, revived the ancient feud between the Thawne and Allen families.
Their deaths protecting Earth from the Dominators were partially instigated by Earthgov President Thawne, Meloni’s father,
who subsequently abducted Don’s son Bart in hopes of converting him to his own nefarious schemes.
- Tornado Twins - Flash (second series) #114 (June 1996) - Oscar Jimenez and José Marzan, Jr.
- Two Families - Legion of Super-Heroes (fourth series) Annual #6 (1995) - Stuart Immonen with Bob Wiacek and José Marzan, Jr.
Adventure Comics #373
- Adventure Comics #373 (October 1968): “The Tornado Twins!” Jim Shooter and Mort Weisinger
This may be incomplete.
- Legion of Super-Heroes v.4 #17 (April 1991): “Earthgov Executes Allen Duo,” Keith Giffen*
- Legion of Super-Heroes v.4 Annual #6 (1995): “Running Scared,” Tom McCraw
- Flash #114 (June 1996): “Race Against Time Chapter 2: Sibling Rivalry,” Mark Waid
- Flash #148–149 (May–June 1999): “Chain Lightning Parts 4–5,” Mark Waid and Brian Augustyn
- Impulse #86–87 (July–August 2002): “Crisis on Impulse’s Earth,” Todd Dezago
* The Tornado Twins were originally contemporaries of the Legion of Super-Heroes, whose members had been teenagers in the 2970s. Their lives in the 30th Century were altered by Crisis on Infinite Earths (1986) and again by Zero Hour (1994).
Pre-Crisis (on the future of Earth-One), they were direct descendants of Barry Allen. They obtained their speed temporarily as part of a publicity stunt for Flash Day, a one-time event honoring their distinguished ancestor. (Adventure #373, 1968)
After Crisis on Infinite Earths, they were still Legion contemporaries, but were now the children of time-displaced Barry and Iris. Dawn was unmarried at the time of their death, and Don had been married not to Meloni Thawne, but to Carmen Johnson. Their son, Barry II, was only two years old when the original Legionnaires were in their late thirties. Their execution by a Dominator-controlled Earthgov is chronicled in a four-page story by Keith Giffen in LSH v4 #17 (1991).
Zero Hour shifted the Legion of Superheroes roughly twenty years later. Dawn and Don were killed by Dominator agents with aid from a still-independent, but no less corrupt, Earthgov in 2980 (LSH v4 Annual #6, 1995), leaving an infant Bart and a two-year-old Jenni, who joined the Legion herself in the year 2995. (It is a bit confusing to consider that Bart, who only existed after Zero Hour changed history, actually arrived early enough in the 20th Century to experience and participate in the event himself.)
Finally, the Legion of Super-Heroes stories now take place 1,000 years in the future, so they suffer from the same “time shifting” as present-day stories. With the LSH as reference point, and Jenni’s age when she joined, we can place the twins’ deaths at roughly 14–16 years before the Legion’s founding, and their birth about 20–25 years before that.
Additional background on XS and the Allen Twins from The Encyclopędia Galactica (which has since disappeared).
** Thanks to Omni Commentator for providing the first appearance information! Also, this story is reprinted in Legion of Super Heroes Archives Volume 8.
Thanks also to Michael Scheu for clearing up how many LSH series there have been.