Ion is the Embodiment of Will in the Emotional Spectrum, birthed at the dawn of time when the Life Entity entered into the universe and sheltered itself on the planet Earth.
As soon as sentient beings developed willpower, Ion was born from the green wavelength of the emotional spectrum. Discovered by the Oans, the immortals contained him within a Power Battery on Oa and kept the entity's existence a secret for eons. With the entity contained, the Oans used his energy to grant themselves, their Manhunters, the Green Glob, the Halla, and the Green Lantern Corps, a portion of its vast powers.
After Hal Jordan as Parallax destroyed the Central Battery, both Ion and Parallax were set free. Ion wandered the cosmos for a time, and eventually was unconsciously summoned by Green Lantern (Kyle Rayner) after his girlfriend, Alex Dewitt, was killed by Major Force.
As a way to cope, Kyle unconsciously expelled his feelings of rage from himself, which took form as Oblivion; a being of energy that eventually manifested itself in the form of one of Kyle's childhood nightmares. As Kyle defeated Oblivion his power seemed to increase until he became bestowed with god-like powers, becoming able to project himself in dozens of different places at the same time and possessing limitless amounts of energy.
Encouraged by his friends, Kyle decided to expel his god-like powers and recharge the Central Battery on Oa, forming new Oans whom Ganthet looked after as he taught them the protocols and responsibilities of being members of the Guardians of the Universe.
Not long after the rebirth of Hal Jordan, the Green Lantern Corps became active once again.
After a period of time as a regular Green Lantern, Kyle was bestowed with the power of Ion once again during the Infinite Crisis.
During the reveal of the Sinestro Corps, Ion was forcefully extracted from Kyle and imprisoned on Qward. Held in captivity by the Anti-Monitor, eventually a group of "Lost Lanterns" rescued Ion from confinement on Qward and returned him to the positive Universe and to Oa.
- In War of the Light Part II players will have to transport the Spark of Ion to the Green Lantern Corps' central power battery.
- Ion first appeared in Rann-Thanagar War #1 (April, 2006)
- Ion is shown to be the first Embodiment of Emotion that was formed due to the Life Entity's influence.