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Official Site: Marvel comics

Infinity Gems, sometimes referred to as the Soul Gems, are six immensely powerful gem featured in the fiction Marvel Universe. Whoever holds all six gems in the Infinity Gauntlet gains omnipotence, omniscience, omnipresence, and God-like power, and has absolute dominion over the universe. In later storylines and cross-over media a seventh Infinity Gem is sometimes added to the primary six. However, a seventh gem has never been used in official canon.

The Soul Gem first appears in the The Power of Warlock limited series, with all six appearing during the second Thanos War storyline in an Avengers and Marvel Two-In-One annual, with Thanos harnessing their latent energies to power a giant gem to extinguish every star in the universe.

In the third volume of the Silver Surfer title, the character refers to the gems as Soul Gems,. They are gathered by the Elders of the Universe, who intend to use their combined power to drain Galactus of his lifeforce and then recreate the universe with themselves with the oldest beings in it (Galactus have lived in the Universe that existed prior to the birth of the current Marvel Universe). This plot is thwarted by the Silver Surfer with several Elders and the gems lost in a black hole, while Galactus consumed other members of the Elders. However in a follow-up story, because the Elders of the Universe were barred from entering Death's realm due to prior machinations of the Grandmaster, Galactus soon found himself being poisioned from within by the Elders he consumed. Silver Surfer, Mr. Fantastic and the Invisible Woman journeyed through the black hole to recover the gems, where Invisible Woman became possessed by the sentient Soul Gem and had her evil Malice persona awakened. She was later subdued and the gems were returned to successfully extract the Elders and save Galactus. The gems then fell back into the possession of the Elders before the beginning of their most famous story.

In the limited series Thanos Quest Thanos refers to the entire set as Infinity Gems for the first time. Thanos systemically subdues the Elders one by one to gather all six gems. Once reunited under his control as the Infinity Gauntlet. This series also reveals the origin of the Gems, with Thanos explains to the Elder of the Universe the Runner that the set are actually the remains of a once omnipotent but lonely being. Unable to endure eternity alone, this entity eventually commits suicide, although a fraction of the being remains and becomes the Infinity Gems.

Infinity Thrall has not been a contender in any CBUB matches.