Fan Fei was born and raised in the heavenly city, K'un-Lun. At the age of 15, she was caught teaching kung fu to the cavemen beyond K'un-Lun's borders. To punish Fei, her students were fed to Shou Lao. Angry, she jumped in the dragon's pit so she could punch Shou Lao once before dying, however, she managed to slay the dragon and win the power of the Iron Fist. For killing their sacred dragon, Fei was exiled from her home.
As she traveled the outside world, she defended the weak humans from the Man-Apes, but vowed never to train them again. This got the attention of Mephisto, who visited her in the form of a snake. When she refused his partnership, Mephisto offered his help to the Alpha Gorilla instead, gifting him the Power Gem to even the odds against Fei.
Fei was injured badly in her fight with the Alpha Gorilla. So much so, she wandered back to K'un-Lun where she was welcomed back with open arms. Shou Lao was resurrected, and her actions had revealed his true nature to her people. She refused and continued traveling the world defending the weak.