Page "The Thanos Quest" Paragraph 8

Thanos's final target is the Grandmaster, a consummate gamesman.

With the final gem, the Mind Gem, imprisoned in a random teleportation device that will only deactivate with his death, he informs Thanos that he cannot have the gem until he bests him in a game of his choosing.

The two then compete in a virtual reality combat game, which Thanos seems to win until it is shown that the Grandmaster had sabotaged Thanos's weaponry.

However, Thanos then reveals that the body with which the Grandmaster had been competing was merely a robotic clone of Thanos ; its destruction being inconsequential, the real Thanos proceeds to destroy the gaming equipment, killing the Grandmaster and freeing the Time Gem.