Unknown God

The Unknown God is the mysterious god responsible for separating the Traveler from their sibling at the start of Genshin Impact.

She appears in the opening cutscene in which the Traveler tells Paimon how they ended up stranded in Teyvat.

When the Traveler and their sibling attempted to leave Teyvat, the unknown god blocked their path. Calling herself the "sustainer of heavenly principles," she denounced the "arrogation of mankind," and engaged the twins in battle. She summons swarms of dark red cubes to attack them (similar to the dark red cubes that ravaged Khaenri'ah), and upon trapping them, engulfs the twins individually within her cubes.

Upon being completely engulfed by her powers, the Traveler fell into a deep sleep and experienced countless nightmares. Once they awoke five hundred years later, their powers had been sealed away and they found no trace of their sibling.

Unbeknownst to the Traveler, their sibling had also awoken from the unknown god's imprisonment at some point and eventually became the leader of the Abyss Order shortly before the Traveler's arrival in Mondstadt.