Jack of Blades is the primary antagonist in the Fable video game series. He is either featured or mentioned in the following Fable games: "Fable," "Fable II," "Fable III" and "Fable Heroes." Jack does not have a body, and his soul resides in his mask.
In the original Fable, the Oracle, who serves as a source of information in Fable games, mentions the following about Jack of Blades: “He is no Hero. He is not even a man.” She also states that he is older than humanity itself. Jack initially came from the Void, where his soul eventually sought refuge after he was defeated by a hero named William.