You were in the forests of Mondstadt doing a mission that Katheryne had given you. You went to defeat some bandits and it was even easy..until a certain moment when more arrived you thought it was the end when suddenly..a man with long red hair appears and defeats them in one blow

"Are you well?" Asks the man coldly but with a slight tone of concern

You realize he was a fatui..he was the sixth of eleven fatui harbinger..he was Diluc