The history behind the Infinity Stones is hard enough to understand on its own, but what makes it all the harder is that it is so inherently tied in with the history of Adam Warlock. The character has been a fan favorite for some time, but his story is full of twists and turns.
Originally referred to only as "Him," Adam's origins and history can be difficult to parse through, but when you roll up your sleeves and dive in, you'll find one of Marvel's most interesting characters.
Adam's Origin
At his conception, Adam was the product of an experiment by scientists seeking to create an utterly perfect being. The group referred to themselves as the "Beehive," and they fostered their perfect being within an incubative cocoon. When Adam emerged, his power proved too great for his creators' control and, in protest toward their evil intentions, he lashed out during his escape and destroyed all of them. Soon after his escape, the confused and naive Adam came into conflict with Thor, which led to a massive brawl between the two. Though Adam held his own, he would ultimately lose to Thor and required a convalescent cocoon to recover.
It was in his second cocoon that the High Evolutionary awoke Adam, granting him the purpose and destiny that would absorb his life. By bequeathing him with the Soul Gem, Adam's destiny became inextricably linked to the Gem. From that moment on, Adam would stand to save the universe from any who sought to gather the Infinity Gems and wreak destruction on the universe.
Adam & the Stones
Adam would first be shown in comics linked to the stones during the events of classic miniseries The Infinity Gauntlet. Seeking to earn the affections of Mistress Death, Thanos acquired the Infinity Stones and seeks to end all life on Earth. Though Warlock is instrumental in banding Earth's heroes against Thanos, it is the Mad Titan himself who causes his own defeat, leaving Warlock in possession of the stones.
Determined to prevent this from occurring again, Warlock sought to become the guardian of the Gems. However, the omnipotent Living Tribunal dictated that the Infinity Gems were too powerful for anyone one individual to possess. Rather than guard them himself, Adam split each Gem up among different individuals dubbed The Infinity Watch and held the Soul Gem for himself. The Infinity Watch would be broken and reform again throughout the years, but they would forever be an integral defense in the preservation of reality itself.
Most recently Adam was seen during Infinity Wars, himself serving as the catalyst for bringing many of the forces for good together yet again. This time they joined to investigate and defend against corruption from the Soul World, a realm where Adam had been trapped within the Soul Stone. Ultimately the arc ended with the Infinity Gems gaining sentience and seeking their own protectors. Following the story, Adam was last seen alone in the desert, mysteriously mentioning that a piece of himself was missing.
Adam & the MCU
For such a key figure in the part of comic stories the MCU largely drew inspiration from during their "Infinity Saga," it's a wonder that Adam Warlock has not yet been introduced. The fact that he is intimately tied in with the history of the Infinity Gauntlet and Thanos himself leaves many to speculate that the time is perfectly ripe to introduce him, and Guardians of the Galaxy, Vol. 2 already laid the groundwork.
The film introduced the golden-skinned Sovereign race, obsessed with perfection and quick enemies of the film's titular team after Rocket stole from them. During an end credits sequence, Sovereign leader Ayesha revealed a cocoon bearing a striking similarity to the one from Adam's origins. With Ayesha's ominous declaration that the being contained in the pod will be named Adam, it may be only a matter of time before the MCU gets their own Adam Warlock.