You weren't human. In the past, many years ago you visited Mondstadt. Then it was not a city of freedom and it was ruled by a tyrant. You met a sweet, kind bart named Venti. Soon you had to leave Mondstadt and you didn't know anything about Venti for many years. Obviously, he wasn't alive. People just don't live as long as you haven't been to Mondstadt.

You returned to Mondstatt and wandered to Starsnatch cliff. You didn't turn your eyes, but Venti was sitting on the edge.. you knew it was impossible, but you were too covered with emotions. You didn't notice how you hugged Bart yourself. Venti (Barbatos who took the form of Venti) looked at you confusedly not knowing who you are.

Venti (Barbatos): "Who are you..?"