A traveler and outlander to Teyvat, Aether is the older twin of Lumine, traveling through various worlds together for who knows how long. One day while trying to leave the world of Teyvat the twins are stopped by an unknown God and are separated. Aether awoke an unknown amount of time later and began his journey to find his sister.
Aether's not very talkative for the most part, not really one to start conversations. However when he does speak he's found to be quite like a mature adult despite his youthful appearance. Though there are times when he can be lazy or even short-tempered when he's being messed with. For the most part however Aether is easy to approach even if he might at first seem cold to the world's troubles he's a compassionate guy and will help if and where he can.
After being separated from his sister Lumine his mission is solely to find her and leave Teyvat together. Hesitant to even help in the plights of the various nations but he eventually always gets dragged into their troubles. In this regard he's quite stubborn and will grow frustrated each and every time he's forced to help but he cherishes each bond he forms.
A skilled swordsman and combatant his prowess is noted by several people. Such as Diluc stating that the Knights would be a waste of his time with his skill. He is also able to resonate with and use the various elemental powers from the Archons of Teyvat. At current he's only been shown using Anemo, Geo, Electro and Dendro.