In the DC Extended Universe film Justice League (2017), Ryan Choi was portrayed by Zheng Kai, but his scenes were cut from the theatrical version.

[2] Choi makes his first appearance in the new Rebirth continuity in the Justice League of America: The Atom one-shot, by Steve Orlando and Andrew MacDonald.

It has been claimed that the impossible feats performed by Ray Palmer during his superheroic career caused the very fabric of reality to warp in Ivy Town's vicinity, making it a nexus of paranormal activity.

Many parties, including the ancient "Cancer God" M'Nagalah and the microscopic aliens known as "the Waiting", consider Ryan a key player in the war and have made attempts to recruit, capture, or kill him.

[3] As the Atom, Ryan has faced numerous challenges, including the shrinking serial killer Dwarfstar, his strict and disapproving father, and being seduced, kidnapped, and even swallowed alive by the size-changing villainess, Giganta.

Ryan Choi was involved in the search for the missing Ray Palmer, traveling into the restored Multiverse along with Donna Troy, Jason Todd and a Monitor nicknamed "Bob".

Literally plucked back to New Earth, he leaves his role of dimension-hopper to Kyle Rayner, returning to defend Ivy Town from a monster invasion.

However, due to Ryan's ability into sorting out the mess, besting the Chronos couple and restoring Ivy to normalcy, Ray finally gives him his blessing.

[12][13] Ryan makes his official debut in the new DC Rebirth continuity as a teenage genius Ivy League college student tutored by Ray Palmer.

[14] Palmer reveals his identity as the Atom and enlists Ryan's help in fighting crime, talking to Ray from his lab in a tech support role.