History
The past history of the Grandmaster of Earth-1815 likely mirrors that of his Earth-616 counterpart. He is one of his realities Elders of the Universe and has focused his life on his obsession with games. Around World War II he and his fellow Elder the Collector discovered the planet Earth and it's large number of super-humans. The Collector sought to add them to his collection, however the Grandmaster suggested they instead wager on the humans. The Grandmaster gambled that normal humans would eventually fear their super-powered brethren and incarcerated them. Thanks to a destabilization of this realities timeline, this would ultimately come to pass in the modern day in the form of Operation: Zero Tolerance.
However the Grandmaster's victory was short lived as the reality hopping Exiles arrived on that world and liberated it's super-humans losing the bet for the Grandmaster. Furious at these unknown interlopers, the Grandmaster confronted Earth-1815's Mangeto and used torture to learn the Exiles identity and their role fixing damaged realities. The Grandmaster then decided to eliminate the Exiles by finding counterparts of them that exist in one reality. The Grandmaster found these exact duplicates of the Exiles on Earth-33629. Upon arrival, the Grandmaster made a wager with his Earth-33629 counterpart to see which team would win. Posing at the Timebroker, the Grandmaster gathered Earth-33692's Blink, Mimic, Morph, Magnus, Thunderbird, and Nocturne and molded them into a team of Exiles. Staging them in a high tech headquarters located at the bottom of the Atlantic, he set the team up as this worlds greatest super-heroes, capturing many of the villains in this reality and incarcerating them.
To this end, he hoped to draw out the reality hopping Exiles and have them investigate his copycat team. When the reality hopping Exiles arrived at the Exiles-33629's headquarters, the Grandmaster (still posing as the Timebroker) ordered his Exiles to attack. All the reality hopping Exiles except for Longshot was captured. Longshot spied on the "Timebroker" and learned his true identity and his wager with his Earth-33629 counterpart. Longshot freed his comrades and they revealed the truth to their alternate reality counterparts. The two teams and all the captured super-villains then confronted the Grandmaster who revealed his reason for manipulating them. When they refused to fight, the Grandmaster slew them all.
This angered his Earth-33629 counterpart, who summoned his realities Elders of the Universe and resurrected the slain super-humans. They beat the Grandmaster into submission and he was incarcerated on Collector-33629's museum world.