Stewart Cadwall was a Hollywood screenwriter whose career was not going well. While he was arguing with his agent, he inadvertently attracted the attention of the omnipotent alien known as the Beyonder, who had traveled to Earth to study humanity. Cadwall was impressed by the Beyonder's powers, so the Beyonder imbued him with powers of his own. A lightning-shaped award Cadwall was clutching was transformed into a sword, and Cadwall imagined a more powerful, armored form for himself, along with a winged horse to ride, and called himself Thundersword.
Thundersword left a path of destruction in his wake, attacking a television studio and fast food outlets. He was soon opposed by members of the X-Men and New Mutants, as well as Dazzler and Avengers Captain America and James Rhodes, then known as Iron Man. Captain America disarmed Thundersword, turning him back into his physically unimpressive normal form.
Cadwall was taken into police custody, but he soon realized his power was not dependent on his sword, and transformed into Thundersword, breaking out of jail. Iron Man fought him again, unsuccessfully, until, thanks to a power boost from an electrical generator, he was able to send him into the Pacific, defeating him.
After being released from prison on parole, Cadwall led a peaceful life with a wife and two children in Van Nuys, California until Captain Marvel and Alpha Flight arrested him for keeping his lightning-shaped trophy. A vision from the Inhuman precog Ulysses Cain had foretold an energy emanation from Cadawall's home was going to cause a tragedy. When Captain Marvel raided his house, it was discovered unnatural energy was building up within the lighting-shaped trophy but hadn't reached dangerous levels at the time. Stewart was arrested for keeping his trophy while he had told the authorities he hadn't, but the Black Panther, Captain Marvel's ally, paid off his bail.
The trophy was later stolen by Philippe Beaulieu, member of Alpha Flight's Board of Governors (and secretly the villain Eshu), from evidence lock-up to empower himself. The fight took Captain Marvel and the Eshu to Earth. Upon landing in a bar, Stewart Cadwall got his hands on the sword and removed its power, rendering Eshu powerless and subsequently subdued. Because of this, Carol allowed him to keep the trophy and both resumed their lives.
Cadwall was given the power by the Beyonder to transform himself into a more physically impressive form, complete with superhuman strength. As part of this transformation, he was able to give himself a set of golden protective armor, a lightning-shaped sword that was able to rend materials like brickwork, and a winged horse that he could ride. Whether Cadwall was able to imagine other weapons and equipment for himself is unknown.
As Thundersword, Cadwall wielded a lightning-shaped sword.
As Thundersword, Cadwall rode a winged horse named Boromir.
- This character was based on Steve Gerber.
- There was a nod to this character in Deadpool: Back in Black #4.
- 4 appearance(s) of Stewart Cadwall (Earth-616)
- 2 appearance(s) in handbook(s) of Stewart Cadwall (Earth-616)
- 1 minor appearance(s) of Stewart Cadwall (Earth-616)
- 1 mention(s) of Stewart Cadwall (Earth-616)
- 1 mention(s) in handbook(s) of Stewart Cadwall (Earth-616)
- 3 image(s) of Stewart Cadwall (Earth-616)