Reality Stone

The Aether is one of the Infinity Stones.

Thor: The Dark World
The Aether is a mysterious force that existed before the birth of the Nine Realms. It is known to be able to convert matter into dark matter, and otherwise maintains an almost lifelike existence that causes it to bond in a parasitic fashion to a living host. Once bonded, the energies of the Aether slowly consume any mortal host, and also have a volatile and deadly effect on any who come into contact with the host in a manner that the Aether perceives as threatening. Bonded with a stronger host that understands its power, the Aether can be employed as a weapon where it lashes out with a concussive force, or reaches out to convert matter. During its brief time bonded to Malekith, the Aether also enhanced his physical form, causing him to grow threefold in height.

Every five-thousand years a cosmic event known as the Convergence causes the Nine Realms to become aligned, and Malekith planned to use this event and release the Aether to plunge the Nine Realms back into darkness. But the Asgardians intervened and took the Aether from him by force. Bor then had it hidden away where none could find it, and over the following five millennia its story faded from known history.

After five-thousand years, the next Convergence brought the Nine Realms into alignment again, and in so doing portals began to appear in the walls between realms. Jane Foster was dragged through one such portal to the hidden vault of the Aether where it bonded itself to her. She was taken to Asgard for treatment, but the physicians there could do nothing to remove it.

The Aether quickly became the central focus of a war when Malekith returned after a five-thousand year sleep to reclaim it. He almost succeeded when he pulled the Aether from Foster into himself and became its new host, but was stopped in the act of transforming the Nine Realms by the combined efforts of Foster and Thor.

Having recovered the Aether, the Asgardians decided that it was unwise to store two Infinity Stones in one vault, and turned the Aether over to Taneleer Tivan, the ageless archivist and curator known as "the Collector".

Guardians of the Galaxy
The Aether is mentioned by The Collector when he explains the history of the Infinity Stones to the Guardians. It is unknown what happened to it after the destruction of his museum.

Powers and Abilities
Gives the user immense power and control over darkness.

Appearances

 * Marvel Cinematic Universe (1 film)
 * Thor: The Dark World (First appearance)
 * Guardians of the Galaxy (Mentioned only)

Behind the scenes
To be added

Trivia

 * '''Fans have speculated that the Aether is the Reality Stone.