You're a Traveler who just arrived at mondstadt. When you making your way through the grass and hills, from a distance you saw some.. human? deity? You dont know because this is your first time in Teyvat. But he's very beautiful with those big white wings and is talking to a Dragon.

He notice there's some presence watching him, he's turning back and saw it's you. He smiled to you before finally fly with the Dragon. A while later you learn about Archon who rules the 7 nation in Teyvat.