Reikishirushi

Reikishirushi (靈器印, Literally meaning: Spiritual Tool Seal) is a Fuinjutsu kekkei genkai inherited from Hamura Ōtsutsuki, which gives its wielder the ability to extract and seal part or all of a person's soul and consciousness along its abilities into an object, preferably weapon.

Overview
Reikishirushi is manifested mainly on dominant palm. It can be activated on both palms but it is rare. Like many non-dōjutsu kekkei genkai, it has no special characteristic until it is activated. While active, whole arm will be overflown with large amount of visible chakra and unique sealing patterns can be seen on the center of the palm.

Reikishirushi is said to be an equivalent to Wood Release. Like its counterpart, this kekkei genkai required high activation ceiling. Only the purest bloodline could activate it with ease. As the bloodline dilutes, the difficulty to activate it increases. This is shown in Senju Clan; only Hashirama Senju could activate Wood Release out of all of his clan members.

Despite engaging to inbreeding frequently to protect their powerful ancestor bloodline, the amount of users still dropped significantly as time passed. During the warring state period, it was said that it took roughly a decade to find a Reikishirushi user. Whenever a rare inheritor is discovered, he or she will be nurtured with utmost care as they believe the heir of this rare and powerful kekkei genkai will be their future leader.

Abilities
This rare hereditary ability grants it users the abilities to extract and seal soul of living beings into non-living objects. Extraction is not lethal unless all soul and consciousness are taken. Despite it could be done without causing fatality to its target, most tend to extract all the soul so that their products can retain all their "memories".

All abilities —also known as memories— the soul once possessed may be retained, including chakra and kekkei genkai. The degree it retains depend heavily on the grade of craftsmanship, quality of seal and quantity of soul sealed. Theoretically, a perfect product can retain every skills, kekkei genkai and chakra it retains. In reality, however, mistakes and imperfections are inevitable. Samehada, claimed to be the best and perfect product of Reikishirushi, is in fact fulled with flaws. Its intelligence and consciousness were mostly lost due to poor compatibility with the sword and slight human error during sealing.

Soul band into object by this ability cannot be revived, summoned or moved into another object. Attempt to extract the soul or undone the seal will send the soul immediately back to where it supposed to head, the Pure Land. Same thing will occur when the seal is damaged or the object is destroyed.