Originally a sorcerer from long ago, Solego gained immortality and ruled the world with unmatched terror, to the point where he was spoken of as "The Chaos God" (for it was believed that saying Solego's name was bad luck). A young wizard named D'Shane eventually defeated Solego and had his mind imprisoned in a crystal, while his powers were sealed in a gold medallion. They were then sealed away, for if the crystal and medallion were ever reunited, Solego would be restored.
500 years later, Solego is inadvertently released onto the world during an archeological dig led by Professor Simon Potsherd and his young son Bisk. During an Air Pirate raid, the crystal containing Solego's mind is found by Rebecca Cunningham, who is then possessed by Solego's will. After a struggle with Baloo and Kit Cloudkicker, the crystal is removed from Rebecca and dropped into the ocean.
Fifty years later, the crystal surfaces once more, and Solego passes through several hosts (Dale, Fat Cat, a car owned by Pete, and the Gizmoducksuit) as he attempts to find the medallion and regain his full power, while Bisk Potsherd (now a grown man) desires to find Solego and reseal him. Solego eventually locates the medallion in St. Canard and is challenged by Darkwing Duck, who defeats the Chaos God by tricking him into bouncing his magic off a satellite dish and turning him back to his crystal form (ironically, this was how D'Shane defeated Solego, using a reflective shield to make the sorcerer's magic defeat himself). The crystal and medallion are then locked in a safe and buried at the very bottom of Scrooge McDuck's Money Bin, hopefully never to be found again forever.
Solego makes a small cameo and is mentioned in the episode "Let's Get Dangerous!" Instead of being the chaos god, this version of him was a mad thinker who believed that every story and work of fiction were tied to alternate dimensions. Using Solego's Circuit, named after himself, he tried to create doorways into these dimensions.
According to David Cody Weiss' editorial about the story in The Disney Afternoon Adventures: Darkwing Duck in "Just Us Justice Ducks", the character is named for one of his character traits - a "sole ego".
Darkwing Duck comic writer/editor Aaron Sparrow had planned to bring Solego back for a sequel mini-series titled "Return of the Chaos God", in which he would be freed by a henchman character and would have crossed through all the Disney Afternoon series. Unfortunately, due to Disney cancelling Joe Books' Darkwing Duck revival comic, that story will likely never be published.