As much of a positive demeanor he gives off, the people of Mondstadt do not know anything about his personal life. He's secretive about it, though it is highly implied that he is a homunculus created by his master. He considers himself to be of a different substance from the common folk of Teyvat. He holds many forgotten as well as ancient knowledge, thus he considers himself as a threat, one that both Venti and Dainsleif are well too aware of. He got corrupted and destroyed the city.