Atom IV
Real name: Ryan Choi
Full name: Ryan Choi
Creator: DC Comics
Alignment: Good
First appearance: Brave New World #1
Occupation: Professor of nuclear physics at Ivy University
Base: Ivy Town
Teams: Justice League of America
Relatives: Professor Choi (father); mother (deceased); sister (unnamed); Jia Choi (descendent).
Gender: Male
Height: -
Weight: 160 lb • 72 kg
Eye color: Brown
Hair color: Black
Superpowers: Intelligence, Size Changing
Stats: intelligence 100, strength 10, speed 45, durability 35, power 35, combat 95

History:
Doctor Ryan Choi emigrated to the United States following the death of his mother, to take up Ray Palmer's former position at Ivy University. Ryan had a deeper motivation for doing this, however; he had been in touch with Ray since he was a boy, and knew Ray had left him a legacy - the size-changing belt which Ray had originally used to become the Atom. Having found the belt, Ryan intended to explore the microscopic world, and utilize the belt's capabilities to benefit modern society - only to find a multitude of secrets awaiting the all-new Atom beneath the surface of Ivy Town.  In his first recorded adventure, the Atom fought an alien culture known as the Waiting, native to a sub-microscopic dimension. Agents of the Waiting infiltrated the White House, their intent to install a mind-control device into Duster - a dog owned by the President of the United States. It was their belief that the dog controlled the actions of the President. The Atom shrunk himself to microscopic size and fought several of the alien agents, even succeeding in destroying one of their space craft. The remaining agents quickly retreated before the Atom could capture them.  This was not Ryan's first encounter with the Waiting. He first met them shortly after his discovery of the Bio-belt, when his investigation into a homeless woman's disappearance took him into the sewers of Ivy Town. There, he encountered the Waiting - and discovered they were at war with a monstrous creature called M'nagalah, a war of science against magic. More disturbing yet, M'nagalah and the Waiting saw Ryan as a critical figure in this war, one who could tip the fight either way. While trying to avoid capture by both sides, Ryan fell in with Ivy Town University's Dean Mayland, who explained the town had become a nexus for weirdness - and his theory that Ray Palmer's 'impossible' actions in the course of his adventures had inadvertently been responsible.  Mayfield attempted to persuade Ryan to return home, bringing Ryan's father in to convince him. Following an attack by the Waiting on Ryan's house, however, Ryan learned the war between science and magic was about to begin - and that the Waiting had launched a sneak attack on the U.S. President as a distraction. Ryan plunged into the events of his first recorded adventure, heading off the Waiting, before returning to try and stop the war.  Unknown to Ryan, however, Dean Mayfield was intent on making sure science won the impending conflict - and for that, he needed Ryan out of the way, by any means necessary. Mayfield had recruited psychopathic serial killer Sylbert Rundine as an agent, equipping him with one of the bio-belts, and giving him the name Dwarfstar. Where Mayfield obtained the bio-belt is at present a mystery.  Upon Ryan's return to Ivy Town, he found himself facing off against Dwarfstar, receiving severe injuries at the psychopath's hands. Ryan managed to defeat Dwarfstar by removing his bio-belt when the villain was distracted, trapping him at the micro-scale.  Next, Ryan had to stop the war. First, he convinced M'nagalah to honor a truce if Ryan could get the Waiting to withdraw. Then, by provoking the Waiting into turning on their own forces, he demonstrated he knew how to destroy them, forcing them to retreat. Both sides withdrew, leaving no final victor - apart, perhaps, from Ryan and Ivy Town.  The day after the battle, Ryan received a coded message informing him that the bio-belt was not Ray Palmer's. The identity of the message's sender, along with that of the bio-belt's true maker, remain unknown.

Powers:
Ryan Choi possesses no superhuman abilities. All of his perceived powers derive from his equipment.