Nathaniel Tryon was a victim of the Reach's experimentation. As Neutron, he was let loose on Central City. Decades later, he became an acquaintance of Bart Allen, and helped him in his effort to change history for the better.
Nathaniel was a runaway who fell into the clutches of the Reach at some point. They experimented on him, and activated his Meta-Gene. In a field test, the Reach encased Nathaniel in a robotic containment suit, which Impulse dubbed as "Neutron". He was programmed to wreak mayhem in Central City, and to seek out and challenge the Flash.
Both Flash and Impulse rushed to challenge him. Due to an omni-directional attack that he kept unleashing, both speedsters retreated, where they met up with Kid Flash. All three speedsters decided to create a whirlwind around Neutron, which would propel him into the sky. In the air, Neutron went critical and blew up himself and a large part of town. The control disk, along with Neutron's containment suit, was destroyed in the explosion.
Neutron reformed himself and was about to blow up again, this time with much greater consequences. He had regained consciousness, but was no longer able to control his power. Flash resolved to speed Neutron to a desert, where he would blow up and not harm anyone. Impulse joined in the task, which ended up with both speedsters tripping due to Impulse's (intentional) misstep as Neutron was about to blow again. Jay Garrick and Kid Flash bailed them out at the last second, allowing Neutron to unleash another explosion. As the speedsters discussed the failed maneuver, Flash stating directly that Impulse tripping them both saved his life, Impulse rushed to a reforming Neutron and applied the pill, reverting him to a human.
At STAR, Nathaniel and the others underwent extensive testing, pushing them to the limit. Though the others frequently expressed concern about the regimen, "Neut", as they had come to call him, did not mind so much. He felt that what the Reach did to them, was much worse.
When the others expressed the intention to escape, Nathaniel argued against it. When they did go through with it, he triggered the alarm.
Taos May 13, post-20:52 MDT
Following Red Volcano's attack on STAR, Neut was guided out of the facility by Ed. Neut thanked Ed for coming back, but Ed was adamant it was only temporary.
After the Reach threat was ended, Neut returned to his foster family.
A depowered and scarred Neutron wearing a prison uniform and Inhibitor collar trusted Impulse to go back in time and prevent the apocalyptic future he had helped create, through such acts as killing the Flash. He gave Impulse a pill of unknown substance that would revert him back into a normal human. After Impulse jumped back in time, Neutron's scars and all evidence that he had ever been incarcerated disappeared, but he realized that the future around him was still the same.
Neutron has the ability to produce and release cascading omnidirectional energy waves which can cause destruction to the nearby environment. The energy waves are released automatically, such that the next energy wave is released before the first energy wave fades. This prevents even speedsters like the Flash from attacking him directly without being hit by the cascading energy waves. Neutron can also release energy blasts from his hands.
Neutron's powers are so destructive that he needs to have a containment suit which stabilizes his energy and prevents him from detonating himself. Neutron has shown to survive disintegration, able to reconstitute himself after being completely dispersed.
Neutron wore a containment suit to stabilize his energy from being detonated and prevent the cause of a huge explosion. The suit seemed to stabilize him by releasing energy in the form of omnidirectional waves.