History
In a primordial era of Earth-616, a god being with the power of Infinity committed suicide out of loneliness and its aspects split into seven Infinity Gems that could grant portions of that power to whoever held them. One of the Gems was lost to a different reality, Earth-93060, also known as the Ultraverse.[1] While the other six carried aspects of the being's influence over external reality, this seventh Gem carried the vestiges of the being's psyche.
At some point it was encased in a slightly larger, spherical pod device through which it embedded itself in the heads of living things to forcibly possess them and direct their actions towards its unclear goals. The minds of its hosts were supplanted, though echoes remained and mixed together with the dominant personality, confusing its motivations and slowing its progress. About twenty years prior to the modern era, the pod possessed soldier of fortune Brian Marmount and from that mind absorbed a strong grudge against his ex-partner, Rick Pearson. After Marmount's death, the pod was acquired by a monk named Lao, who was killed around the same time the other Infinity Gems had found their way into the Ultraverse. The proximity of the other Gems reawakened the Ego Gem, spurring it to move its hosts more aggressively, though the corruption from the other minds it had possessed still obscured its own goals. First, it briefly reanimated the monk's corpse while it was being airlifted along with other bodies by agents of Aladdin. The zombified monk attacked the pilots, crashing the plane into the Atlantic Ocean. From there, the pod possessed a passing shark. The shark continued west and beached itself near Houston, Texas, where it was discovered by Antony Hernandez, who would become the pod's final host. Driven by Marmount's memories, Hernandez made his way to an abandoned Alamo Base, where he found a machine that was once used to turn Marmount into a cyborg and subjected himself to it, becoming the living weapon known as Mannequin.[2] With Marmount's mind in near total control, Mannequin pursued vengeance against Pearson, now known as Eliminator. Through serendipity, Eliminator's current partner was also Antony's brother, Carlos. Carlos attempted to get through to his brother as he and Eliminator pursued Mannequin to a bridge in Chicago, where he attempted to strike through Pearson's estranged family. Mannequin didn't respond to Carlos' pleas and even killed him, enraging Eliminator into crushing Mannequin's head to end the fight. The pod fell out and rolled into the water afterwards.[3]
Another refugee to arrive from Earth-616 at this time was Sersi, whose powers and connection to its home reality made her sensitive to the call from the Ego Gem. She flew to Chicago to retrieve the pod from the river where it had fallen, cracking it open to reveal the Gem inside. It came to rest on her forehead, and without the other personas absorbed by the pod, it recalled its original goal for the first time. Sersi retained enough of her own will to convince the Ego Gem to allow her to seek out her companion, Black Knight before finding and reuniting with the other Infinity Gems.[1] Finding him alongside members of UltraForce and learning that the other Gems had been assembled by Loki, she attempted to use the team as pawns to retrieve the Gems. Loki's newfound power made him completely unapproachable, however, and he only toyed with the members of UltraForce while leading them to believe they were fighting for the Gems.[4] She then came across Grandmaster, who had come to the Ultraverse looking for his lost Mind Gem, and devised another plan. Grandmaster was able to approach Loki with a challenge to a game with knowledge of the seventh Infinity Gem as his prize. His rapport with the Mind Gem made him immune to Loki's telepathy. Loki agreed to participate and won the game, but his "prize" came in the form of Sersi, who only wanted a chance to get close to Loki so the Ego Gem could merge with the other six. The Infinity Gems incarnated into a being called Nemesis, who attempted to use her creative forces to remake the two universes.[5] Even the seven Gems together did not make a cohesive whole, however, and the Ego Gem's consciousness found itself at odds with some of the voices of the other Gems. This weakness allowed heroes of the two universes to fight back against her, and ultimately Black Knight struck a decisive blow on her crown where the Gems were stored, destroying the Ego Gem and scattering the other six in an explosion of creative force that would send everyone back where they belonged while restructuring the Ultraverse from the ground up.[6]
The remains of the Ego Gem's essence was split among the Power, Soul, Mind, and Space Gems, allowing them each to take on autonomous living forms that shared Nemesis' malicious intents. The Time and Reality Gems, whose individual consciousnesses rebelled against the others in the interest of preserving the fabric of existence, remained in their original forms and found other hosts in the reforming Ultraverse to mitigate the chaos in Nemesis' wake.[7]