This Naruto papercraft is the Shiki Fuujin, the cube craft paper toy is designed by blackignus. Shiki Fuujin is a Fuuinjutsu technique developed by the Fourth Hokage. A variation of this technique was used to seal the Kyuubi within Naruto. The technique was taught to the Third Hokage who later used it in battle. After calling forth the Shinigami (Death God) with the proper hand seals, the user will hand over their soul in exchange for the Death God removing the soul from his target. The ultimate sacrificial jutsu, this technique can be used by a Kage Bunshin, but the Death God will still remove the original caster's soul.
With the jutsu activated, a spectral form of the caster will appear in front of the Death God. The Death God will push his arm through this spectral body, and the arm will extend from the chest of the real caster. This forces the caster to be close or grasping his target. The arm will reach out into the body of the target, and draw their soul from their body. If the Death God is unable to remove the whole soul because of the near death of the caster, it can remove it's knife and merely slice off a portion of the spectral form's soul to consume. This will render the targets corresponding body part dead and useless. The soul portion removed will then be sealed within the chest of the caster. Both the soul of the target and the caster will never pass into the afterlife. They will be condemned to suffer in the Death God's stomach for all eternity, locked in a hated combat, never to escape.
Shiki Fuujin, a Fuuinjutsu or sealing technique, is the Fourth Hokage's original technique which he used in sealing the nine tailed demon fox or Kyuubi to Naruto's body.
The Third Hokage during the battle against Orochimaru, used this technique to stop Orochimaru who at that time, used his forbidden summon technique to summon the souls of the First and Second Hokage.
Being a Ninja Professor or Master of all techniques in Konoha Village, the Third Hokage was able to use this technique too although he is not the original creator of it. According to him, Orochimaru who mastered almost all the techniques of different villages is still ignorant about it.
This is a forbidden technique in the sense that the Fuujin user's soul will be sacrificed in the exchange of using this. The soul will be hand over to the Death God. Those who have their souls sealed with this technique can never go to heaven, instead they will suffer inside the Death God's stomach. The souls of the sealer and the sealed one will intertwined in hate and forever locked in combat.
But in the case of the Third Hokage, sealing out the soul of Orochimaru is quiet impossible. Although he successfully sealed off the souls of the First and the Second Hokage but he has no enough strength left to seal off Orochimaru's soul.
But the Third Hokage has an alternative just to stop the ambition of Orochimaru, that is to destroy Konoha Village, the Third Hokage sealed off the techniques of Orochimaru. Orochimaru couldn't use his hands anymore and soon he will die.
After the sealing is complete the soul of the sealer will be consumed by the Death God too. This is the time when the sealer will die, just like what had happened to the Third Hokage.
You can download this cube paper craft toy from here: Naruto - Shiki Fuujin Cube Craft Free Paper Toy Download