The Traveler's Sibling, also known as the Prince/Princess, is the lost sibling of the Traveler. The primary goal for the player in Genshin Impact is to travel through Teyvat, meeting the Archons to find a way to reunite with their sibling.
The gender and name of the sibling entirely depend on the player's choice at the beginning of the game during their fight against the Unknown God. If the player chooses female, the lost sibling is a male named Aether, while if the player chooses vice versa, the lost sibling becomes a female named Lumine.
The appearance of the sibling is nearly identical to the Traveler, no matter which gender is picked.
Both siblings have blond hair, slim body builds, golden-yellow eyes, and fair skin. They seem to be physically around their teenage years, being shorter than adults but taller than most children.
Aether wears a black breastplate vest along with a white scarf-cape with golden embroidery. He wears black pants, dark gloves, and black boots. His hair is medium cut with a long braided ponytail.
Lumine wears a white sleeveless dress with tail capes and bracers covering her thumbs, with white stockings plus boots. Her hair is medium cut with short straight twin tails.
Thus revealed, certain parts of both siblings' clothing lights up based on their current element. In the opening cutscene, both siblings are seen with glowing white lights.
While the player's light will change based on gameplay, the sibling's light seems to remain white thus far.
Not much is known about the personality of the sibling.
During the beginning cutscene in Genshin Impact, both siblings are fighting against the Unknown God. Depending on which gender the player so chooses, they will have a name attached to them and will become the Traveler. The other sibling (Aether or Lumine) will then be attacked by the Unknown God and be sent away in the form of a cube. The Traveler will then continue to fight before being subdued and having their powers sealed away, sent to wander the land until they come across Paimon.
It's currently unknown what duration of time passed in between the sibling's arrival vs the Traveler's. Though it is speculated to be around 500 years, due to the great disaster that happened to Teyvat in which the sibling witnesses. During the period in between the Traveler's arrival, the sibling has gained control over Ruin Guards alongside gaining a new power in the Abyss Order as of recent.
During the adventure of the Traveler through the city of Mondstadt, the sibling discovers that their other is alive and is ecstatic. Unfortunately, they say to themselves that they cannot reunite until they have finished their own journey around Teyvat.
In an advertisement for Genshin Impact paid for by miHoYo named "We Will Be Reunited", also uploaded to the official Genshin Impact YouTube channel, the Traveler's Sibling is depicted as Lumine, watching her brother travel the world and fight monsters from the hand of a Ruin Guard, unbeknownst to her brother. Lumine says:
"We will be reunited. But not here, not now."
- While the elemental powers of the sibling may not be revealed as of yet, their clothing still emits the white light that is seen on both siblings in the opening cutscene when they meet the Unknown God.
- While the Traveler is seen with the same clothing, the spots that emit light changes throughout gameplay to represent their current elemental use after borrowing power from the statue of the seven of the region they are currently visiting.
- Throughout multiple videos on the official Genshin Impact Youtube channel, it is revealed that Lumine should be the canon lost sibling, while Aether becomes the Traveler.
- Though the sibling may exhibit an antagonistic behavior throughout the game as of V1.0, it is not confirmed that the sibling has negative nor evil motives as suggested by the official teaser: We Will be Reunited.