Aether (Earth-6531)

"Malekith found a weapon out of the darkness and it was called the Aether. While the other relics often appear as solid objects, the Aether is fluid and everchanging. It changes matter into dark matter. It seeks out host bodies, drawing strength from their life-force."

- - Odin to Thor and Jane Foster

The Aether is one of the Infinity Stones, which represents Reality. Unlike its fellow Stones, the Aether features unique qualities as it appears as a liquid as opposed to a solid object.

History
"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."

- - Odin The Aether is one of the Infinity Stones, henceforth being one of the singularities one of the universe, with the Aether representing Reality. It can change the laws of physics and the universe around it to convert anything into dark matter. Unlike its other sister stones, the Aether takes a liquid form.

The First Dark Elf War
The Aether was eventually discovered by the Dark Elves of Svartalfheim, one of the Nine Realms, led by Malekith. They seized its power during the Convergence, an event which sees the Nine Realms aligned through a series of wormholes. The Dark Elf leader crafted a plot to use the Aether to plummet the galaxy into darkness to ensure the survival of his race, but he was stopped by the Asgardians, who decimated nearly the entire race and took the Aether. Then king Bor hid the Aether, as it was impossible to be destroyed.

Second Dark Elf War
In 2013, when the Convergence was about to restart, the Aether was accidentally found by Jane Foster in London, England. The Stone infected Foster, who became its host. Returning to Earth, she showcased powerful energy projection that killed whoever touched her after she witnessed two police officers trying to apprehend her. This attracted Thor's attention, who took her to Asgard and Odin. The Aether's return caused Malekith to return from his deep sleep, who arrived on Asgard, ensuing a battle. Frigga ultimately died attempting to protect Jane from the Dark Elf and his servant, Kurse. They fled before being able to acquire the item.

After the Bifrost was interdicted by Heimdall, Thor unwillingly recruited the help of his adoptive brother Loki into finding his hidden passages through the Realms, until they were able to arrive in Svartalfheim, now a barren wasteland. There, the brothers plotted to fool the Dark Elves, who believed Loki was on their side, and they succeeded in extracting the Aether from Jane's body. After Loki's apparent sacrifice, both forces went to Earth, where Thor and Malekith battled for the control of the stone, sending them to different worlds such as Jotunheim. The Aether was eventually taken by Thor and sent to Asgard, but then sent to the Collector in Knowhere.