Shinigami

The is the spectral entity summoned through the usage of a unique sealing technique.

Background
Minato Namikaze, the Fourth Hokage, first summoned the Shinigami, as a last resort, with the intention of sealing Kurama into his infant son. However, as he wasn't capable of sealing Kurama's entire chakra, due to its size, he was forced to seal only the yang half. Using the Shinigami, Minato was able to seal the yin half of the tailed beast within himself, going on to use another sealing method to seal the other portion of the fox within his son.

Appearance
The Shinigami is a translucent spectre with a demonic visage. It is much larger than an average human, possessing long, shaggy white hair, from which two red horns protrude, and red-coloured skin. It is draped in a large white garments and carries a set of prayer beads. The Shinigami is almost always seen with a tantō in its mouth. When removed, however, its mouth is revealed to be full of sharp, jagged teeth, and a very long, almost serpentine tongue.

When sealing a target, a series of curse marks will spread across its arms.

Abilities
The Shinigami's main strength lies in its ability to forcibly extract the souls of both its summoner and its summoner's target, cut them free with its tantō, and seal them within its belly. It does this through the Dead Demon Consuming Seal technique, primarily used by Minato Namikaze and Hiruzen Sarutobi. Through the use of a special mask, stored within the Uzumaki clan temple outside of Konohagakure, the contents of its stomach can be released.