Kitetsu (妖刀 「鬼鉄」 Youtou Kitetsu?, lit. Demonic Blade: Ogre Steel) is the weapon of choice used by the infernal Dark Samurai, Doku. It is a cursed Tachi that feeds on the souls of those slain by its blade. Doku went back to using this after he gave the Dark Dragon Blade to the Vigoor Emperor. To get this weapon, you must explore the arena in which you battle Doku for the second time. Whenever it is equipped the player must proceed to destroy enemies as the cursed sword will leech off of Ryu's life meter. To stop the vampiric effect completely, the player must equip the Armlet of Tranquility. In Ninja Gaiden Black and Ninja Gaiden Sigma, this vampiric effect is no longer present and Ryu's health will not be drained when using the Kitetsu.
- Dark Rain: X, X, X
- Stab of Overpowering Evil: X, X, Y
- Dead Soul Bind: X, X, Forward X, X, X, X, X, X, X, X
- Soul Eraser: X, X, Forward X, Y
- Blade of Nirrti: X, Y, X, X, X, X
- Izuna Drop: X, Y, X, X, X, Y
- Stab of Extinction: Y
- Haze Straight Slash: Hold Y
- Extinction Straight Slash: Hold Y (Essence Technique)
- Bassara: Hold Y (Ultimate Technique)
- Crazed Bones Slash: Forward X
- Azure Dragon: Forward Y
- Scarlet Dragon: Forward + Hold Y
- Behead Dragon: (While running) X, X
- Thunderclap Kick: (While running) Y
- Hundred Curses Slash: Circle Y
- Fiend's Bane Kick: (While blocking) X, X
- Gleaming Cross: (While blocking) Y
- Fiend Sealer: Y next to downed enemy
- Blade of Nirrti: X, X, X, X
- Izuna Drop: X, X, X, Y
- Helmet Splitter: Y
- Air Destruction Slash: Forward + X
- Falling Dragon Blade: Forward + Y
- Flying Swallow: (While jumping towards enemy) Y
- Guillotine Throw: (While jumping over enemy) Y
- Cicada Slash: X or Y
- Flying Swallow: (While wall running) X or Y
- Divine Cicada Slash: (During Flying Bird Flip) X or Y
- Ripple Slash: (Floating on water surface) X or Y
- Wave Reverser: (Floating on water surface) X, X or Y, Y
- Gleaming Water Dragon: (Underwater) X or Y
- Floating Blade: (Underwater) X, X or Y, Y
- In Ninja Gaiden Black it is possible to cancel the blade's vampiric effect on Ryu by upgrading the weapon to Level 3, while in Sigma the blade does not drain Ryu's health at all.
- The life-draining effect of the Kitetsu doesn't kill Ryu right away. It takes about 5 to 6 minutes for the blade to completely drain his health.
- It is possible to cancel this effect by equipping the Armlet of Tranquility (only present in Ninja Gaiden).
- The Dead Soul Bind attack is capable of draining the health of enemies and healing Ryu, however this cannot be used on boss characters (Except Doku himself, but only when you get the upper-hand during a sword-clash). During this animation, Ryu is rendered invincible.
- The Kitetsu can actually be split into 2 separate swords. This is most clearly seen during its Ultimate Technique, Basara, where Ryu splits the sword into two, launches a flurry of slashes, then spins the swords.
- It is believed that this was the base concept for the creation of the Dual Katanas, Dragon's Claw and Tiger's Fang.
- The only moves Ryu and Doku share are Dead Soul Bind and Stab of Extinction.
- Kitetsu is translated as "Ogre Steel" and is a popular name for a sword tainted by demonic aura and bloodthirst.
- 'Ninja Gaiden Sigma, if you perform Kitetsu's UT while it's in Level 1 or 2, Ryu instead performs Dragon Sword's UT.