Jomo Kimayne's origin is unknown. He was first shown as a member of a race who had sought to avoid an ecological disaster by placing all their members into a never-ending VR hallucination, which would allow them to interact socially, keeping their minds and sanity keen.

Within the scenario, which was an urban environment called "Shadow City", Jomo led a double life: by day a secretary for one of the wealthiest women in the city, by night its vigilante protector - Lockdown.

Lockdown's life continued its eventful-if-cyclical pattern, until a group of interlopers - the Fantastic Four - landed on his planet. Caught by the robotic security, they were added to the program as a group of villainous "paraforms" known as the "Tetrad". However, they were then able to manage the impossible, and escape the simulation, before being spirited away by a malfunctioning teleporter. Lockdown, roused from the simulation with his accomplice, Rosetta Stone, as a protective safeguard, came to the conclusion that the Fantastic Four were a threat to the safety of the people of Shadow City, and vowed to stop them, by any means necessary.

Later, he and Rosetta Stone arrived on Earth during a "contest of champions" being arranged by an alliance of aliens to trick the superheroes of Earth. The two heroes were instrumental in defeating the aliens and saving the heroes.

Nothing has been seen of them since then; possibly they had a conversation with the Fantastic Four and went home.

Night Cruiser

• There has been no connection shown between Jomo Kimayne and Jomo Kimane, a character created by the same writer less than a year prior to his first appearance.