Originally known as Dr. Baldhead, the renowned medical genius. However, when he was operating on a young girl one day, she died. At this, the doctor lost his mind, becoming a serial killer and subsequently being thrown in prison. One night, after the events of Guilty Gear, he was visited by the ghost of the young girl who died, who assured him that her death wasn't his fault. After this moment, Dr. Baldhead was never seen again, but a "new" doctor named Faust appeared. From this point on, Faust set out to make up for all those who he murdered by helping others. Over the course of the Guilty Gear games, Faust finds himself chasing down assorted characters who he deems dangerous to the populace, and searching for any information he can find about the true cause behind the young girl's death.
Faust's fighting style is exceedingly unorthodox, fighting with a giant scalpel and a series of very strange special moves. His iconic special move, "What's Next?" involves the throwing of one of several different items which are randomly determined. These items (which vary depending on the games) include :
- A hammer, which deals damage and can make the opponent dizzy
- A poison vial, which releases a cloud of poison gas
- A coin, which deals light damage and powers up another special move (similar to another character, Johnny, who throws coins to power up his Mist Finer)
- A miniature version of a character, who crawls towards the opponent. Later games added further variation to this move, with one of three "minis" possible:
- Mini-Faust, who hits the opponent once
- Mini-RoboKy, who can hit twice
- Mini-Potemkin, who can hit up to three times
- A bomb, which blows up in a large explosion which can damage both Faust and his opponent.
- A chamber-pot like device, which deals damage and knocks the opponent down.
- A donut, which can be walked over to regain a small amount of health
- A candy bar, which similarly fills a small amount of Tension gauge
- A meteor which flies into the sky and causes six meteors to fall down, dealing heavy damage.
Other moves that Faust uses include teleporting moves that involve Faust disappearing underneath a blanket and inexplicably appearing in another location by falling out of the sky or opening an enormous door, which can damage the opponent. His super moves are similarly insane, including a multi-item version of "What's Next?." In general, the very unpredictable fighting style Faust uses makes him a difficult character to learn, but also a very frustrating character to fight.