Dallas Riordan's father and most of her family were police officers so it was natural for her to go into the 'family business'. After some time with the NYPD she became an aide to the mayor of New York City. When the Thunderbolts appeared after the disappearances of the Avengers and the Fantastic Four, the city embraced them as their new hero team so the mayor appointed Dallas as liaison between his office and the new team of "heroes". Dallas like everyone else was completely unaware that her new associates were really super villains in disguise. The ruse was to use their new found publicity to get access to Avengers files and gain their security clearances with which they could take over the world.
Dallas quickly began a flirtation with Thunderbolt member Atlas and the two were dating when the group was exposed as villains. The Thunderbolts, led by Citizen V but was now revealed to be Baron Zemo, made their attempt to take over the world and fled to a satellite Zemo had acquired. In order to save face, the mayor chose to blame Dallas for leading him astray and promptly fired her.
Dallas Riordan was created by Kurt Busiek and Mark Bagley, and first appeared in Thunderbolts #1 (1997) as the Thunderbolt's government liaison.
Major Story Arcs
Becoming a Superhero
A short time later, Dallas was approached by Roger Aubrey of the V-Battalion and he offered her the role as their main field operative Citizen V. The original Citizen V, John Watkins, was a Golden Age hero murdered by Helmut's father Baron Heinrich Zemo. The true grandson of the original Citizen V was in a coma so when they offered Dallas the role they implied that she was descended from the original. It turned out that Dallas's grandfather had worked for the original V-Battalion and and had survived the death of most of the V-Batallion at the hands of Heinrich Zemo. He had served in World War II but stayed in Europe to help recreate the V-Battalion with Roger Aubrey and various others leaving his wife and son behind. His son Jim Riordan raised Dallas to be tough and encouraged her desire to be a police officer like him. Jim did not like the V-Battalion but he presumably wanted his daughter to be ready if she ever accepted a role in the V-Battalion (as was her right, being a descendant of a member).
Furious over the way her life had been destroyed by the Thunderbolts, Dallas decided to take down Zemo and the Thunderbolts herself. At first she wore a padded costume that made her appear as a man in order to confuse her enemies and secure her secret identity. She began to menace Baron Zemo blowing up his Mexican castle and swore vengeance against the Thunderbolts down even after Hawkeye began to lead them. The V-Batallion managed to locate the Thunderbolts and she planted surveillance devices in the cabin they were using at the time in preparation of the next phase of the operation. She observed them first fighting Charcoal and then fighting USAgent and the Jury which resulted in the destruction of the cabin and her surveillance devices setting them back to square one.
With the destruction of his Mexican Castle, Zemo retreated to one of his South American strongholds his father had built and enslaved the local populace. As Citizen V, Dallas went to South America and organized a resistance against Baron Zemo's tyranny, though Captain America attacked her thinking Zemo was behind the Citizen V mask. Captain America immediately recognized that Dallas wasn't Zemo and even guessed that she was a woman wearing a padded costume and they began to work together. It was Cap's influence that inspired her to remove the padding and surprise everyone that she was a woman and fight for justice rather than vengeance. Baron Zemo and Techno managed to capture Citizen V and were going to fire her into the atmosphere attached to a rocket but Captain America arrived in time to release her. However the rocket was still launched and Dallas leaped onto it to disable it before it reached altitude. When the guidance system was disabled the rocket fall back to Earth destroying the stronghold and Cap thought Citizen V perished but she managed to glide to safety thanks to her cape.
Dallas returned to the states to continue tracking the Thunderbolts and followed them to Robinette, Nebraska which was being attacked by the Masters of Evil. When the Crimson Cowl activated a weather device and retreated to safety, Dallas confronted Hawkeye telling him that she would bring down his Thunderbolts even if he stood with them. Hawkeye though pointed out that the Masters of Evil are the real threat and that his team was saving the townspeople which should be her priority. Ashamed that she didn't see the big picture she sought out the device creating the storm but was knocked out from behind before she could disable it. The Crimson Cowl captured her and used her as a scapegoat when her plan failed. After her command pod crashed she teleported to safety and teleported Dallas into the wreckage with a non-functioning version of her own Crimson Cowl. Still angry at the Thunderbolts for past betrayal and for them believing she was the Crimson Cowl she didn't even speak in her own defense as she was arrested.
While Atlas was visiting Dallas in prison the V-Battalion broke her out she was too valuable to remain incarcerated specially since they knew she was innocent. She got right back to work trying to track down the Crimson Cowl for framing her but instead found herself fighting the Imperial Forces of America ( The Secret Empire) which had ironically, but unknown to her, been funded by Baron Zemo. While the Thunderbolts fought the Secret Empire's Brute Force and Shocktroopers, Citizen V called the Jury who had been publicly hunting the Thunderbolts. When the Jury arrived they could tell the Secret Empire was the greater threat so they helped the Thunderbolts while Dallas destroyed the illegal research they had amassed through their experiments. Having seen the Thunderbolts fight yet again for justice and protect innocents she began to see them as actual heroes and maybe her vendetta served no purpose. The V-Battalion next ordered Dallas to assassinate Henry Peter Gyrich because Gyrich and the CSA had been compromised by the nanite conspiracy spearheaded by Baron Strucker of HYDRA. They did not give her any information as to why Gyrich needed to be killed, just that it was necessary and that if she refused they would merely replace her. Dallas refused and the V-Battalion sent their operatives to stop her and she had to fight back against people who had been her friends. By disobeying the order they considered her a traitor but she said that asking her to assassinate Gyrich was them betraying her.
Completely dismayed having been betrayed again by people she considered friends she made her way to Paris in order to decide her next step. Making her way back to America sought out the Thunderbolts for help but they were attacked by the V-Battalion with their flagship the Vanguard. Dallas revealed herself to have been Citizen V the whole time and that the V-Battalion had been the ones that broke her out of prison but she revealed to let them tarnish the name of Citizen V like Baron Zemo had. However before Dallas could inform the Thunderbolts of the V-Battalions plan she was kidnapped yet again by the Crimson Cowl. Finding herself naked within a completely dark cell Dallas was faced with the Crimson Cowl again and immediately began plotting her escape. Once she managed to use the automated food deliverer to hotwire the cell door she soon found her Citizen V attire and formulated a plan. With her Citizen V equipment she generated an EM pulse to disable the Crimson Cowl's technology and the two fought while Crimson Cowl tried to escape. The battle ended when the Crimson Cowl flung Dallas over the railing from her landing pad. Dallas kept from falling by clinging to the Crimson Cowl's cape but she was willing to unclasp her cap revealing her identity in order to cause Dallas to fall presumably to her death. As Dallas fell she thought only of Atlas whom she still loved but luckily she survived her fall into the river below though her spinal column was crushed. The river carried her to Latveria where she washed up and was cared for despite wearing a costume with elements from the flag of the United States of America.
It was from a hospital bed in Doomstadt that Dallas witnessed Atlas explode during a battle with the Scourge on live television pirated from Symkaria. Confined to a wheelchair, Dallas soon began to get visions of her ex-boyfriend Atlas as red ionic energy. At first she thought she was just seeing things but once she was freed from Latveria by the Redeemers she began to investigate the possibility that Erik was trying to contact her.
The Thunderbolts, who had previously disbanded, reunited during a battle with Graviton. Dallas reasoned that the ionic-powered Erik's visitations were similar to Wonder Man's visitations of the Scarlet Witch, who he used as an emotional anchor to tie him to the world after he had been killed. Erik didn't have a body to come back to and instead channeled his ionic energy into Dallas. In their ionic state, Dallas's body could walk and had various super powers. Atlas rejoined the Thunderbolts to fight Graviton but after the battle, Erik and Dallas found themselves and their teammates marooned on Counter Earth. When they returned, the ionic energy recreated a powerless Erik Josten and Dallas retained a portion of the ionic energy. Thanks to the Fixer, Erik soon gained Pym Particle-related powers again.
Dallas joined the Thunderbolts as Vantage and chose to remain on the team to watch Zemo, who she could not trust. Eventually Helmut was scarred by a deranged Moonstone trying to save Captain America. The Thunderbolts briefly disbanded and Erik asked Hank Pym to strip him of his new powers. Dallas and Erik broke up and Dallas took a job working for homeland security.
Erik soon rejoined the Thunderbolts despite being powerless. After an encounter with Genis, Erik became enraged and tapped into his ionic powers which somehow left Dallas paralyzed again.
Commission on Superhuman Activities
Dallas is currently a fulltime member of the CSA and even helped organize the recent battle between the Thunderbolts and the New Avengers. Dallas and the CSA are apparently working with Zemo to save the world from some nebulous threat. Dallas does not trust Helmut, but has so far given him the benefit of the doubt.
Altered again by the Wellspring, during a battle against the Grandmaster in which he had to surrender his powers temporarily to Zemo, Josten was left stuck in a giant form, too heavy even to move and communicate. However he was able to send back some ionic energy to Dallas, restoring her legs.