Summoning: Impure World Reincarnation

Summoning: Impure World Resurrection is a forbidden technique used to revive the dead. The ninja will first sacrifice a living person to provide the vessel that the dead soul will inhabit. The dead body will then be encased in ash and dirt to resemble the soul of the person that was resurrected. When the ninja wishes to recall the souls, a portal will open in the ground and the caskets holding the bodies will appear. When the caskets open the bodies will be grey and in a state of minor decay, requiring a special seal to restore their appearance. At this point, the revived person remembers their former lives, and thus not under the users control. The same seal used to restore their appearance also wipes the soul of its free will, putting them under the users control. This technique can also be used to summon multiple people at once, depending on the amount of sacrifices and the chakra level of the user.
 * Name:
 * Type: Kinjutsu, S-rank, Supplementary
 * Users: Orochimaru
 * Hand Signs: Tiger-Snake-Dog-Dragon

Once complete, the revived is impossible to kill by normal means. If a limb is destroyed or removed, it will simply regenerate. To kill the revived, the soul has to be removed. When the Third fought against the revived First and Second Hokages, he had to create shadow clones and perform the Dead Demon Consuming Seal on both of them to kill them. In doing so, the bodies turned back to ash and dust, with the bodies of the individuals sacrificed to lay among the ashes.