Sealing Jutsu: Reaper Death Seal

The Dead Demon Consuming Seal is a sealing technique developed by the Uzumaki clan to call upon the power of the Shinigami.[2]

Usage
After the hand seals are performed, the user's soul is partly separated from their body and suspended behind them. Behind their soul appears the Shinigami, which restrains their soul with its hair. Only the summoner is able to see the Shinigami at this point. Eventually, the Shinigami wraps its left arm with prayer beads and chants unintelligibly until a cursed seal appears on its arm. It then drives its arm into the summoner's soul, thus allowing the summoner to call upon the Shinigami to seal a target. The technique can either be initiated at close-range,[3] immobilising the target while their soul is extracted, or from a longer range.[4] The Shinigami's arm emerges from the summoner's body and grasps the soul of the target, enabling the target to see the Shinigami as well.

Once the target's soul is grasped, the summoner can remove the target's soul and seal it into their own body. Hiruzen was able to seal multiple souls by using this technique in conjunction with the Shadow Clone Technique.The sealing, however, is not necessarily complete nor automatic; for example when Hiruzen used it on Orochimaru, he had to rely on his own physical strength to extract Orochimaru's soul. Because he lacked the strength to fully do that, he opted instead to only seal Orochimaru's arms, accomplished by having the Shinigami cut off the arms of Orochimaru's soul; this paralysed his arms and prevented him from performing hand seals and by extension most ninjutsu.[5] When Minato uses it, he seals only the Nine-Tails' yin chakra, leaving its yang chakra alone;[6] this sealing of its yin chakra into himself makes him its jinchūriki.

After the sealing is performed, a mark appears on the summoner's stomach that is similar in appearance to the Eight Trigrams Sealing Style. For a few moments afterwards the summoner can continue moving and speaking, allowing them to finish any lingering business they may have. Shortly afterwards the Shinigami will consume their soul and the soul of their target(s), ending their life. The souls of those trapped within the Shinigami's stomach cannot enter the Pure Land and are destined to fight with their victims for all eternity.[7]

The only method of releasing a soul from the Shinigami's stomach is to wear the Shinigami Mask, allowing the wearer to be possessed by the Shinigami.[8]

Trivia

 * After his soul's arms were sealed, Orochimaru physical arms started to rot which caused him increasing amounts of physical pain. He was able to temporarily escape the pain and decay by switching bodies, but still remained unable to make full use of his arms.[9]
 * During his discussion with Kushina on how to deal with the Nine-Tails, Minato stated: "The fūinjutsu I — not being a jinchūriki — am able to use is… the Shiki Fūjin!" (「人柱力なでいオレができる封印術は屍鬼封尽!」, "Jinchūriki na denai ore ga dekiru fūinjutsu wa Shiki Fūjin!") What he meant by this is unclear as the Hokage did not elaborate.[6]
 * Although the technique isn't seen, the first game to mention it is Naruto: Konoha Ninpōchō, the prologue showing that the Fourth Hokage used the technique to seal the Nine-Tails.
 * In the manga and anime, Hiruzen calls this technique "Sealing Technique: Dead Demon Consuming Seal" (封印術・屍鬼封尽, Fūinjutsu: Shiki Fūjin). The technique's databook entry drops the "Sealing Technique" part.