In Ninja Gaiden, Ryu is brought back to life as a "soldier of revenge" by a falcon, the spiritual animal of the Hayabusa clan. Seeking vengeance, Ryu learns those that raided Hayabusa village were from Vigoor. Ryu eventually destroys Doku's spirit, but with his dying breath Doku casts the blood curse on Ryu. The only way for Ryu to lift the curse is to kill the emperor. Once accomplished, he recovers the Dark Dragon Blade, but loses it.
The fallen Blade lands at the feet of a figure, the Dark Disciple, who has been shadowing Ryu. Taking the Blade, the Disciple reveals himself to be the clan leader Murai. He admits that the raid on Hayabusa village was part of his plan to restore the Blade's evil power, using souls harvested by Ryu.
Below are the characters on the site that cosplayers have depicted.