Tornado Twins

Don and Dawn Allen

In their first appearance, the twins are 30th century descendants of Barry Allen. They temporarily gain super-speed powers during "Flash Day", a ceremony honoring their ancestors.

After the events of Crisis on Infinite Earths, the history of the DC Universe is changed. In this new continuity, Barry Allen briefly joins his wife Iris in the 30th century, where the two manage to conceive the twins. Before they are born, however, Allen is killed saving the remaining worlds from the Anti-Monitor.^[1] Don and Dawn are raised in an era of extreme xenophobia, where metahuman activity is unwelcome. Growing up hearing the stories of their heroic father from their mother the two twins, who have inherited their father's superspeed powers, operate as superheroes in secret. They disguise themselves by spinning rapidly, so that they resemble two tornadoes. During this era they meet a time-travelling Wally West, who inspires them to fight the 30th century's prejudice against metahumans.^[2]

As an adult, Don Allen marries Meloni Thawne; they are the parents of Bart Allen,^[3][4] the speedster hero who is first known as Impulse, before maturing into the Teen Titan Kid Flash, and who later becomes the fourth Flash. Dawn Allen marries Jeven Ognats, and gives birth to Jenni Ognats, who would become the Legionnaire XS.

The Twins' fate has changed with each of the DC Universe's major temporospatial disruptions, although they usually involve death in some way. Post-Crisis on Infinite Earths, they were killed helping the Legion of Super-Heroes fend off a Dominator invasion during the Five Year Gap (a timeline in which Jenni did not exist).^[5] Post-Zero Hour, the Dominator invasion occurred about 15 years before the Legion's existence; President Thawne, a corrupt descendant of the supervillain Professor Zoom, arranged for the Twins' murder several months after their children's birth.

The Final Crisis: Legion of 3 Worlds miniseries reveals that the post-Zero Hour characters (including both Meloni and Jeven Ognats, Jenni's father and Dawn's husband) originated on the same Earth as the post-Infinite Crisis version of the Legion (which was introduced in "The Lightning Saga").^[6] Thus, continuity revisions have been made: after Barry's death in the original Crisis, the Twins and their families (Bart and Jenni having already been born) became the target of Professor Zoom, who was attempting to sabotage Don and Meloni's marriage. Both families escaped to Earth-247 (the post-ZH timeline) and the Twins died soon after in unknown circumstances. Both cousins were reunited with their grandmother Iris, and both also rapidly aged to teenagers within days (one can assume that Jenni's rapid-aging stabilized under her own volition, as she never showed signs of it during either Legion series in which she was featured).

In the current issues of Flash, a confrontation with Eobard Thawne, who had captured Iris and brought her to the future, showed a future of Barry and Iris in which Don and Dawn were villains. They hated Barry because his duties as Flash had caused him to spend almost no time with them. It is later revealed to be false while the Renegades investigate Thawne's death (as their display have shown).

Jai and Iris West

In Flash vol. 2 #225 (October 2005), Linda Park, wife of the current Flash Wally West, gives birth to the twins Jai and Iris West II. The West family is stuck in a parallel world for almost a year after the combined Flashes attempt to subdue the evil Superboy Prime,^[7] but return to the DC Earth in Justice League of America #10 (August 2007). Due to a side-effect of their superspeed powers, Iris appears to be approximately 10 years old, while Jai appears to be 8. Wally has referred to his twin children as the "Tornado Twins," and is helping them follow his footsteps. Although they are connected to the Speed Force, they manifest it in different ways; Iris can vibrate through objects (taking others with her), and Jai can "superaccelerate the myofibrillar hypertrophism in [his] muscular tissue" to gain temporary super-strength. Neither of them have ordinary super-speed, although Iris briefly possessed it when their powers were in flux. Their powers require complex machinery to remain stable.^[8] Their accelerated growth spurts and their unstable powers are later revealed as the byproduct of a deep connection with the Death Aspect of the Speed Force, physically embodied by the Black Flash. Wally manages to fight him one last time, severing his bond with his offspring, whose aging patterns and powers are finally stabilized.

Originally neither of them possessed super speed, but while temporarily aged by the Death Aspect of the Speed Force, they exhibited the ability to develop it. During the events of Flash: Rebirth, Iris reveals that the reason their powers are the way they are is because they are literally fighting over the speed force and to continue to do so will kill them. Iris then draws all the power into herself and finally becomes a speedster. She is then stabilized by Jesse Quick, who recently regained her connection to the Speed Force. Iris West then becomes the new Impulse.

Other Versions

On Earth-22, Wally West also had twins, Iris and Barry West. Of the pair, Iris West shows a personality very similar to the spunky, driven and restless personality of her alternate-universe namesake, and, while aged, she had her very same physical appearance, while Barry is more laid-back, broody and aside from the friendly bickering with his sister, inclined to follow every one of her ideas. Both twins have identical super-speed powers, but only Iris became a superhero.