The Infinity Stones have long been Marvel Comics's most compelling cosmic artifacts, due both to their mysterious nature and unlimited power, and they've certainly always held an allure to the mad titan Thanos. However, when he set out to assemble the Stones, they were known by a different name — one which held a clue to their dark secret purpose.
The very first appearance of an Infinity Stone occurred in 1972 in Marvel Premiere #1. It was originally a solitary Soul Gem, used to power Adam Warlock’s cosmic abilities, and later revealed to be one of six. Thanos's journey for the stones begins in Thanos Quest #1 with him peering into the Infinity Well and telling Death he needs the six Soul Gems to complete the task of killing half the universe. Part 1 of the issue concludes with Thanos in possession of the Power Gem, the Soul Gem, and the Time Gem, with him plotting for the others.
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In Thanos Quest, Jim Starlin and Ron Lim set the precedent for Thanos's strength and cunning by demonstrating his power levels without the stones, while also introducing important lore that is still used today. Thanos ruminates that the name «Soul Gems» is misleading because the stones possess unique individual powers, with only one commanding the power of the soul. Thanos completes their retcon as a set of six by changing their name to reflect their nature, deciding on ‘Infinity Gems.' However, this change hides the fact that the Soul Stone is different in nature from the rest — something which became incredibly important in Marvel's later Infinity Wars event.
In the comics, the Soul Stone is shown to have a consciousness and want to be reunited with the others, suggested
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