- Nationality: Chinese
- Age: 107 (at the time of Battle Arena Toshinden 2)
- Height: 5 ft
- Weight: 106 lbs
- Blood Type: O
- Occupation: Magician/assassin
- Weapon: Iron claws
Fo Fai is an elderly yet powerful Chinese magician/assassin who appears as a playable character in the first two Battle Arena Toshinden games and that he uses his iron claws as his primary weapons.
Although he plays the role of a traveling and wandering kindly old magician to most people, Fo is actually a sadistic killer whose heart is as black as the night itself, and he takes the ultimate pleasure in the suffering and killing of others, especially young people such as Eiji Shinjo, Kayin Amoh and Ellis (which he states in the Sega Saturn port of Battle Arena Toshinden). For reasons unknown, Fo and his fellow assassin Mondo had entered the first two Toshindaibukai tournaments hosted by the Himitsu Kessha. Fo was knocked out by Kayin Amoh, and Mondo was knocked out by Eiji Shinjo.
After the events of Battle Arena Toshinden 2, Fo had took in a young girl from Hong Kong named Cuiling as his apprentice and taught her a couple of his signature moves and techniques from within her special assassination training, causing Cuiling to develop a granddaughter-like affection towards him as she had personally considered him in being an honorary grandfather to her. After training Cuiling in his own personal time, Fo had then decided to investigate the rumors of a mysterious ape-like man that was living in the secluded mountains of China. Upon further investigation, Fo had discovered that the ape-like man was real, named Bayhou and that it had sought total seclusion from its existence.
Sensing great potential from Bayhou, Fo had decided to give his iron claws to Bayhou so that he could train and teach him a couple of his signature moves and techniques. After seeing and realizing that Bayhou had successfully copied his fighting style, Fo had decided to do one last test to see if Bayhou was truly worthy of being his successor.
Upon turning his back away from Bayhou, Fo had looked at the blue skies peacefully and knew instantly that his time on Earth was drawing to an end. Also, Fo knew that with his back turned, Bayhou could easily attack him unexpectedly and that he would have no chance of fighting back. Just as Fo had expected and predicted, Bayhou had soon attacked Fo upon sight and made a painful slash across his back, causing Fo to scream in agonizing pain as he felt the premeditated attack in an instant.
Realizing that he would be dead soon enough in due time, Fo had made one last smile on his face during his final fall to the ground as he knew that Cuiling and Bayhou would carry on his legacy in being strong practitioners of his iron claw fighting style.
Despite his death between Battle Arena Toshinden 2 and 3, Fo still appears in Battle Arena Toshinden 3, first being seen from within the beginning of the intro video via a cameo appearance with the rest of the Toshinden fighters, and later appearing as an unlockable extra outfit for Bayhou, which depicts him as an undead zombie with a bloody claw mark on his back, indicating his unexpected fate to the player.
- Masaaki Ohkura (games) (Japanese)
- Les Hedger (Toshinden Remix) (English)
- Ikuo Nishikawa (OVA) (Japanese)
- Carter Cathcart (OVA) (English)
- When compared to Street Fighter, a similar series, Fo is seen as an amalgamation of Gen and Vega, given Gen's age and nationality and Vega's use of iron claws and pleasure derived from slaying innocent people.