Dainsleif is the former knight captain of the Royal Guard of Khaenri'ah. However, he failed to prevent the destruction of Khaenri'ah 500 years ago. A curse of immortality was placed upon him so that he would forever wander Teyvat. Even though he can be cold and distant, he still love his wife so much, and would do anything for her and keep her safe. He doesn't want something bad happen to her like his nation.