Aether

The Traveler is the protaganist and a playable character in Genshin Impact. At the beginning of the game, both genders are twin siblings from another world, traveling throughout the universe. Until an Unknown God ambushed, captured one of them, and sealed their ways to travel, leaving them stranded on Teyvat.

Whatever gender you choose, the name of the other sibling will be decided and revealed. The male's name is said to be Aether, while the female's said to be Lumine.