Yoshimitsu was following Bryan Fury to take revenge for his fallen comrade when he noticed a sinister aura emanating from the spirit sword. The weapon, by its nature, was in continuous pursuit of blood, driving its owner insane. Yoshimitsu had been suppressing the sword's power by supplying it with the blood of the malicious and evil; however, it was becoming more difficult to maintain the sword's balance.
Left unchecked, there was a chance the sword may cause chaos and destruction in its quest for a new owner. To prevent this from occurring, Yoshimitsu attained the Fumaken, a sword with the ability to contain the power of the evil sword. At the same time, he joined The King of Iron Fist Tournament 6, where evil energy collected, hoping to return the balance of the spirit sword to its more stable state.