Origin

Io is a four thousand year-old guardian of the Moon Temple. For reasons hitherto unknown, his mystical essence became entwined with the Half Moon Talbak (mask), meaning whoever wields the talbak is bonded with him. The only stipulation for being able to wear the talbak is to be a chosen descendant of the Joseon Dynasty, meaning at minimal the owner must be Korean or of Korean heritage.

Io's story in modern Marvel begins with a young girl named Dan Bi. Her father had a antique shop. When her father came into trouble with Arthurian sorceress Morgan Le Fay, Dan Bi came into contact with her henchmen. As she fled, she found a mystic mask lying on the bed of her father. When she took the mask to her face, a strange bear-like entitiy named Io appeared and helped Dan Bi. Calling herself Crescent, she and Io vowed to keep one another safe.

Creation

Io was created Danny Koo, Bill Rosemann and Jeehyung Lee for the digital Marvel game Future Fight. His Comic book debut was in War of the Realms: New Agents of Atlas issue 1 (2019), by Greg Pak.

Major Story Arcs

Marvel Voices

After numerous adventures with the New Agents of Atlas, Crescent and Io are officially inducted as members of the team. Staying in one of the team's bunker bases in San Francisco, Io and Bi are sharing ice cream and watching a scary movie together when "intruders" (actually Moon Girl and Devil Dinosaur) set off the base's proximity alarm. The two humans and their companions tussle until Jimmy Woo breaks intervenes, clearing the confusion but admonishing Bi for going on the attack and damaging the base. Realizing she needs to be in a proper educational environment Woo, as her legal guardian due to her father's continued missing status, sends Crescent and Io to the Pan-Asian School for the Unusually Gifted. Arriving in Mumbai, Bi is welcomed by her new teacher Professor Sanjar Javeed, but she soon feels overwhelmed by her classmates who are older than her (especially the Dul Twins, who call her lame for not having inherent powers). Feeling dejected, Bi is ambushed in the corridor by the Dul Twins, who steal the talbak and use their duplication powers to create another, summoning Io and a clone Io.

Dan Bi attempts to take the original mask off Brody Dul, but he uses Io to hit Bi across the hallway. Physically and emotionally hurt, Bi asks Io if he's betraying her because she stayed up past her bedtime. Io, clearly fighting his oath, states that Brody is the owner of the talbak and now his master. The commotion is interrupted by Bi's classmate Gang, who helps her up and tries to be a hero by standing up to the two bullies, however they shove him in a locker and crack his helmet. Bi lies injured and betrayed, but Gang activates the Battle Mode on his mobility suit, retrieves the Half Moon Talbak from the Dul Twins, and returns Io to Crescent. Io apologizes to Bi, insisting that he would harm intentionally bring harm to her of his own free will, and the two reconcile. Together, the trio of Crescent, Io and Gang beat the Dul Twins and Eo in front of a crowd of students, and Io destroys the clone mask due to the misuse of power. Enraged at being defeated, the Dul Twins merge into their Oni form and begin attacking Io before Professor Javeed intervenes. Io returns to the talbak and Dan Bi is ordered to see Javeed in his office, where Jimmy Woo is waiting for her. Agent Woo suspends Bi for starting a fight in school, but commends her for learning a lesson and apologising to the Dul Twins.