Thanos soon found himself challenged by the alliances of the entire universe's greatest heroes, which included the Avengers and Guardians of the Galaxy. This quest even forced Thanos to sacrifice his beloved Gamora, in order to take the Soul Stone. During his mission, both Thanos and his Black Order invaded multiple planets and slaughtered thousands to gain the stones, including Loki and the Asgardians. Thanos then engaged in a ferocious crusade in order to obtain the Infinity Stones. Fed up with all his subordinates' ongoing failures, Thanos made the decision to seek and procur the Stones himself, and he began by forcing Eitri to create the Infinity Gauntlet for him so that he would be able to wield the power of the Stones safely. However, both alliances cost Thanos much of his resources, including the Mind Stone and the loyalty of his daughters, Gamora and Nebula.

Thanos forged alliances with Loki and Ronan the Accuser in order to track down some of the Stones. To complete this goal, Thanos set about hunting down all the Infinity Stones, being confident that the combined force of the Stones would grant him sufficient power. Thanos was a genocidal warlord from Titan, whose own main objective was to bring stability to the universe by wiping out half of all life at every level, as he believed its massive population would inevitably use up the universe's entire supply of resources and perish. To feel so desperately that you're right, yet to fail nonetheless.

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