Fujiwara No Mokou was formerly an ordinary human, but she became an immortal being after drinking the Hourai Elixir about 1300 years ago. Now she is never able to die, though she still feels the pain of injuries as normal. She's considered to be very powerful, given her long life, the power she earned through her life, and her immortal status since she can keep fighting until she can no longer stand the pain. Perhaps due to being ostracized for so long, Mokou is a loner by nature..