Dead Demon Consuming Seal

This seal invokes the powers of the death god (shinigami). Once called upon, the death god hovers behind the user and inserts its arm into their soul. At this stage only the user can see the death god. To perform the seal the user need only grasp the target. The death god's arm extends from their chest and grabs the soul of the target, immobilizing them and allowing them to see the death god as well. The death god then performs the sealing.

Soon after the sealing is completed the death god consumes the soul of the user, sentencing them to an eternity in its stomach. If someone's soul is sealed with the death god, their soul is also consumed. A swirl-pattern is left on the stomachs of those that have had something sealed within them using this jutsu. There is a limit to how much chakra can be sealed by the Dead Demon Consuming Seal, Minato Namikaze explained how it was physically impossible to seal away all of the Nine-Tailed Demon Fox's chakra, opting instead to seal half in himself, and the other half in Naruto Uzumaki. Minato also implies that it is impossible for a jinchūriki to perform the seal.

Hiruzen Sarutobi used the Dead Demon Consuming Seal to try and seal Orochimaru's soul. Because he lacked the energy to do so, he opted to instead seal Orochimaru's arms. After the death god cut off Orochimaru's soul's arms, his physical arms suffered from necrosis, causing him extreme pain and leaving unable to use them. Orochimaru believed a talented medical-nin, Tsunade, could heal the damage the seal caused.

There are many mysteries surrounding this seal, and the exact workings seem to be known to no-one. One of the mysteries is how the Fourth Hokage managed to use this technique and leave behind some of his chakra and personality to act as a fail-safe capable of communicating with Naruto, in addition to observing what Naruto saw. Also, Hiruzen managed to use this technique through the Shadow Clone Technique to seal the souls of the First and Second Hokage before he went after Orochimaru with his original self.