John Deegan

"My name is Dr. John Deegan, and I, like most of you, I'm a psychiatrist. Do you know what my patients tell me the most? They feel inferior. I'm here to tell you, whether we admit it or not, some people, they're just born lucky, which leads us to the real problem, imperfection. How can we ever hope to feel like supermen or superwomen without first becoming super ourselves?"

- John Deegan

Dr. John Deegan is a psychiatrist from Gotham City.

Biography
Deegan was giving a presentation on the treatment of his patients. Before he started talking, all who attended immediately left, much to his disappointment. As he walked to his car, he was approached by the Monitor. The individual destroyed his car to demonstrate his power. When Deegan asked the individual what he was, he remarked that he was something beyond his comprehension. The individual then gave Deegan a book and told him to show everyone what a real god could do.

When Oliver Queen shows up at Arkham Asylum he recognize him and tells him that he dosn't want to bring reality back and runs away after releasing Arkham's inmate. Later when he was about to rewrite reality, Supergirl appears and took the book from him.

Later the Monitor appears with the book in his lab and ask him to think bigger and he rewrites reality again.

Personality
"Idiots!"

- John Deegan

Deegan appears to want to help in his own way through rewriting reality of people's history.

Former Powers

 * Kryptonian physiology: While becoming Superman through Book of Destiny, John's capabilities are no greater than a normal human of his physical conditioning. However, once charged by the energy spectrum of a yellow sun, he becomes able to perform various inhuman feats.
 * Solar energy absorption: While John's powers are dependent on the energy spectrum from a yellow sun, the stored up energy allows him to use his powers without constant exposure to the solar radiation until finally depleted.
 * Accelerated healing factor: John's solar charged metabolism accelerates his healing and allows him to burn calories at a fast rate, making him resilient to weight gain.
 * Self-sustenance: Due to the effects of a yellow sun, John's physical needs are greatly reduced or completely removed, as he does not need to eat or sleep unless he has to.
 * Contaminant immunity: John has an immunity to all forms of disease and contaminants on Earth.
 * Flight: John is able to manipulate his own gravitational field to generate thrust and propel himself through the air at tremendous hyper-sonic speeds, much faster than he can travel by foot.
 * Heat vision: By concentrating every solar energy reserve he has in his body, John can emit blue energy beams of variable intensity from his eyes.
 * Invulnerability: With his cells supercharged with solar energy, John's bodily durability is considerably stronger than even the densest of Earth's metals such as steel.

Abilities

 * Escape artist: John was able to plan his escape from Arkham Asylum in case the superheroes realized that he was behind the changes to the timeline, successfully escaping from Green Arrow and the Flash with the use of prepared traps and distractions, and later managing to improvise and slip away from under Supergirl's watch.
 * High intellect: John Deegan is an accomplished scientist, a psychiatrist and a researcher, although his methods border on torture and conflate with illegal experimentation.
 * Teaching: Aside from his job at Arkham Asylum, John also works as a professor.
 * High reflexes: John possesses incredible reflexes for a human of his age and build, "slippery" enough to escape the Flash, Green Arrow and Supergirl.
 * High speed: John possesses high speed for a human of his age and build, "slippery" enough to escape the Flash, Green Arrow and Supergirl.

Equipment

 * Book of Destiny: Mar Novu bestowed unto Deegan a book which allows him to alter reality.
 * Black Superman Suit: As he posed as Superman of Earth One, he wore a black protective suit.

Behind the scenes

 * In the comics, John Dee, also known as Doctor Destiny, is a supervillain with the power to bring dreams to reality. He is an adversary of the Justice League of America and is prominent in Neil Gaiman's The Sandman series.
 * Doctor Destiny is associated with Dreamstone, artifact created by Dream of the Endless, while his Arrowverse counterpart uses Book of Destiny, artifact created by Dream's older sibling Destiny.
 * Deegan's actor, Jeremy Davies, previously appeared in Constantine as Ritchie Simpson.