- "Long before the birth of light there was darkness, and from that darkness came the Dark Elves. Millennia ago the most ruthless of their kind, Malekith, sought to transform our universe back into one of eternal night. Such evil was possible through the power of the Aether, an ancient force of infinite destruction."
The Reality Stone is one of the six Infinity Stones, the remnant of a singularity that predates the universe, which represents the fabric of Reality. Liquified into a dark red fluid called the Aether (pronounced ēTHər), the Dark Elves and their leader Malekith intended to use it to bring eternal darkness upon all of the Nine Realms. Taken from the Elves by the Asgardians, it was later entrusted to the Collector following the conclusion of the Second Dark Elf Conflict. During the Infinity War, the Aether was retrieved from the Collector's Museum in Knowhere and solidified by the Mad Titan Thanos, who put the Stone inside his Infinity Gauntlet.
The Reality Stone is a remnant of one of the six singularities which existed before the universe. After the universe came into existence, four cosmic beings known as the Cosmic Entities forged the energies of these singularities into six immensely powerful objects called the Infinity Stones. This stone represents reality, as it possesses the power to bend the very laws of reality and physics, converting matter into dark matter.
The Dark Elves
The First Attempt
The leader of the Dark Elves of Svartalfheim, Malekith, used the Reality Stone to create the weapon called the Aether. Every five-thousand years, the Convergence causes the Nine Realms to become aligned. In 2988 B.C., Malekith planned to use this event to release the Aether and plunge the nine realms into eternal darkness; however, the Asgardians intervened and took the Aether from the Dark Elves by force, watching as the race was apparently decimated in battle. Bor then had the Aether hidden away where no one could find it, and over the following five millennia, its story faded from known history.
The Second Attempt
In 2013, near the beginning of the Convergence, a portal opened up to where the Aether was located; Jane Foster happened to walk through this portal and, through curiosity, made contact with it, causing it to become active and infest Foster's body, using her as a host. After arriving back on Earth, Foster exhibited an immensely powerful energy projection when being touched on the arm, and was taken to Asgard by Thor where the Aether was discovered by Odin. During this time, Malekith sensed the Aether's activity and attempted to retrieve it by attacking Asgard. In the end, through the sacrifice of Frigga, Malekith and his army left before he could obtain the Aether.
Later though, when access to the Bifrost Bridge had been restricted, Thor, with a dying Foster, got Loki to take them through a hidden passageway to Svartalfheim. After getting there, they confronted Malekith and through various circumstances, the Dark Elf drew the Aether from Foster and into himself and left the planet. Both parties then arrived on Earth, where Malekith used the Aether to battle Thor across worlds during the Convergence, which resulted in Malekith's destruction. Afterward, the Asgardians were able to contain the Aether, which was later given to the Collector for safekeeping, not knowing the true intentions the Collector had.
Wielded by Thanos
Several years later, Thanos traveled to Knowhere and took the Aether from the Collector, solidifying it into the Reality Stone and adding it into the Infinity Gauntlet. He used it to create an illusion to trap the Guardians of the Galaxy and then briefly rendered himself invisible while talking to Gamora before revealing himself and using the Reality Stone to easily turn Drax and Mantis into pieces of matter and then transformed Quill's upcoming blast from his blasters into bubbles before warping away.
Thanos would use the Reality Stone again to turn Gamora's dagger into bubbles so he could thwart her attempt to kill herself. He later used the Reality Stone to first show Doctor Strange how Titan once was before he then began fighting half the Avengers, Guardians of the Galaxy and Doctor Strange. He used the Reality Stone to transform a large chuck of debris that he destroyed into swarms of black crystals when Iron Man slammed it on him and in his duel with Doctor Strange, Thanos used the Reality Stone to negate his dimensional gate before finally ending the fight by combining the Stone with the Space Stone to pull the sorcerer to him.
Upon arriving in Wakanda, Thanos used the Reality Stone to imprison Black Widow and finally to wipe out half the universe in conjunction with all the Stones, even after Thor severely wounded him with Stormbreaker using all his power.
As the Infinity Stone that represents and governs over reality, the Reality Stone grants its user absolute control over reality itself. However, like all other Infinity Stones, due to it being the most powerful artifact in existence, it can only be wielded by beings of sufficient power and inside beings of no powers, it will inevitably kill them, as evidenced with Jane Foster. The Reality Stone's power is so great that it is capable of affecting reality on a universal scale, as Malekith would have been able to use the Stone to cover the whole universe in darkness. It is also indestructible, as not even the immensely powerful Thor wielding Mjølnir could destroy it.
Those who fully understands its capabilities can remove the Reality Stone from others and safely absorb it into themselves granted they had the necessary level of power needed, as Malekith was able to draw the Infinity Stone out of Jane and merge with it. Their physical powers are greatly enhanced, as evidenced when Malekith was on par with Thor in terms of raw strength and he was also capable of quickly regenerating lost limbs and enduring Thor's blows without any significant damage, with Malekith only being vanquished by having his own ship collapsing on him. Malekith was also able to use the Reality Stone's powers over reality to send out blasts of energy strong enough to cause Thor wielding Mjølnir trouble blocking them and harm the nearly invulnerable Asgardian and even teleport, shown when Malekith suddenly appears in front of Thor. While fully unleashing the Stone's power on the Nine Realms, Malekith also grew in size to roughly three times Thor's height.
When inserted into the Infinity Gauntlet and wielded by Thanos, it is shown that, when harnessed by a user who fully understands and masters its capabilities, the Stone is able to warp reality to a greater extent than previously perceived, as Thanos, with his strong understanding and mastery of its powers, proves able to skillfully warp reality more powerfully than Malekith's display of the Stone's power over reality, achieving numerous powerful capabilities that he very effectively employed.
From the Reality Stone, Thanos acquires the power to create highly elaborate physical simulations and illusions of false realities over a wide range of influence by altering reality in said area to whatever he wished. Prior to the Ambush in Knowhere, Thanos used the Stone to create a false illusion of himself interrogating the Collector in a completely deserted Knowhere, in order to fool the approaching Guardians of the Galaxy and mask the colony's true status as burning down and utterly ruined, rendering himself invisible in the process. The false reality was so convincing that the false Thanos could physically interact with others, and could fight with and be killed by Gamora. Again, prior to the Battle of Titan, Thanos used the Reality Stone to alter the reality around the planet Titan to show Doctor Strange its former beauty in its peaceful prime, in a time before it became an uninhabited wasteland.
Another powerful capability that Thanos gains from the Reality Stone's control over reality is the power to warp and transmute matter into anything he wished. While often doing this to turn and use objects in his surroundings offensively, Thanos displays that the Reality Stone's transmuting powers can even affect living organisms. With a single blast from the Stone, Thanos easily incapacitated Guardians Drax and Mantis by temporarily warping their physical bodies, splitting Drax's body into pieces and turning Mantis into still-conscious strips of flesh, after which they eventually restored themselves to normal after Thanos left the area.
Thanos was able to also use this ability discreetly and silently, as when Star-Lord reluctantly attempted to execute his teammate and lover, Gamora, to prevent her capture by Thanos, the Titan silently transmuted his Quad Blasters to harmlessly fire bubbles, before transforming the weapon itself into bubbles, and would later do the same to Gamora's dagger on Vormir to prevent her from committing suicide.
During the Battle of Titan and Battle of Wakanda, Thanos used the Reality Stone's powers very effectively in combat, transmuting a field of ship wreckage into a swarm of bats to attack Iron Man, and manipulating the ground to spawn a cage of stone pillars to trap Black Widow.
Thanos also displays that the Reality Stone can be used in conjunction with the other Stones to expand it's effects. Combined with the Space Stone, Thanos can manipulate the terrain at such a scale as to pull a flying Doctor Strange into his hand, by pulling the surface of Titan itself towards him. In conjunction with the Soul and Time Stones, Thanos could also heal fatal injuries he had sustained (discounting those caused by the Stones themselves), managing to fully heal the near-fatal wound caused by Stormbreaker as he teleported away with the Space Stone.
After the Infinity Gauntlet was completed and the Reality Stone's power reached its full potential, alongside the other Stones, it allowed Thanos to wipe out half of all sentient life in the universe with a simple snap of his fingers. However, using all six Stones in this manner at such a weakened state caused the Stones's combined power to nearly overwhelm him, and the Gauntlet and his left arm were left scorched by the release of energy.
The Aether converts matter to dark matter, and seeks out host bodies in order to draw strength from their life force, i.e., energy from living organisms, thereby sapping them of energy in a process that would inevitably prove fatal. As used by Malekith, the only one who fully understood its capabilities, it was capable of creating tendrils of itself or spikes to strike out at opponents, regenerate lost limbs, and create a tornado of energy.
Whilst bonded to a strong host like Malekith, the Aether greatly enhanced his physical strength and durability, thereby allowing him to fight Thor on a reasonably even basis. On its own, the Aether is capable of sending out shockwaves filled with its energy and pulses of power that can throw back any who it deems a threat to itself. These blasts have been enough to easily stun beings as physically powerful as Asgardians. The Dark Elves and Malekith appeared to have a connection to in that it awoke them from hibernation when the Aether was used again and Malekith could sense the Aether's location.
- In the comics, the Collector owned the Reality Gem before Thanos took it from him.
- The large structure which contained the Aether is called the Chamber.