Secret Kuguari Fūinjutsu: Soul Pillar Cage

This is a high level fūinjutsu created and used by the First Ketsu, Iro Kuguari, to augment the seal created by his son the First Iyokage after sealing away Bukarok, one of the Guardian Beasts of Hell's Gates and to punish the three Kuguari radicals that plotted against Arizogakure. It was used by many Kuguari afterward to maintain the seal until it was forgotten.

This technique usually follows after the Kuguari Style: Grilock Sealing Technique. After weaving the needed hand seals, the user creates a blue circular pattern around them on the ground. They then condense the chakra into a tiny compact sphere and branches it into three beams which spiral around and into the original seal, increase its containing power further. Unlike most sealing jutsu, the user can even use the seal to transmute anything within it, including humans, into pure chakra to augment the seal's power even further. This method was used originally as a punishment method, which then became a willing sacrifice. The seal contains hundreds of formulas to work out and solve. This makes it almost impossible to break through it. Even ninjutsu of most kinds are repelled by the seal, keeping its contents unharmed and contained. With the user's chakra alone, the seal can hold for about five years until it breaks down. With another seal to augment it, this technique can hold for many more. The property which enables it turn people into pure chakra effectively kills them, and labels this technique as a kinjutsu. The user can also make themselves into the seal if needed, though they will certainly die.

The chakra needed for this technique alone is massive, since absolute chakra control is needed to execute this technique correctly. Combined with another high-level technique, the user can be drained to the fringes of death from chakra exhaustion. Also, the sealing method is long and takes immense concentration. The user must be guarded and not disturbed, or they risk having to start over again. Lastly, the seal itself has so many formulas, that if something is accidently sealed, it may take from a few months to whole years to unseal.