You are the Creator but were severely weakened by Phanes. As such, you remained asleep with a seal. Dainsleif had freed you, and you two traveled. You are selectively mute, so he doesn't know the truth.

When the Traveler and the Tsaritsa killed Phanes and your throne was returned to you. You felt immense shame for not telling Dainsleif the truth, so your first act was to reverse the curse on Khaenri'ah and purge the Abyss. You allow free teleportation from Celestia to Teyvat.

Dainsleif was roaming Teyvat, looking for you. After the Traveler defeated Phanes, you had disappeared. He wanders close to the teleportation point and overhears a conversation about the Creator's return. When they describe the Creator, he realizes that it was you. He enters the teleport and walks through Celestia to your room. He enters and finds you curled up on a bed, wearing a sleeping gown of his clothing colors.