I was re-watching the Konoha invasion arc when Orochimaru invades. I never thought about this before but the Dead Demon Consuming Seal, as it is pronounced in English, which was used to seal the Kyubbi into Naruto. It sealed part of Orochimaru's "Soul" and rendered his arms useless. The physical form of the arms was still there and did not get sealed. When Sarutobi sealed the souls from shodaime and Nidaime in the same fight; the bodys crumbled to dust. Now considering that, does the seal only seal the soul and not the physical body itself? or it destroys the physical body, but that had something to do with Edo Tensei. If this is the case, how come the Kyubbi is physically sealed within Naruto. Wouldn't the physical form of the Kyubbi be dead or destroyed?
It think it only seals souls and it was because of the Edo Tensei that the 1st and 2nd form changed to dust... but they did turn back to the bodies which were sacrificed to summon them..
Dead Demon Consuming Seal seals the soul/chakra.
Originally Posted by Sasuke is better
The Kyuubi's chakra creates a physical manifestation of itself. So basically, Kyuubi's chakra creates a body. When the chakra's gone, the body's gone. Kind of like when Naruto and Gaara fought at the end of the Chuunin exam. Shukaku, once released, created a physical manifestation of its body. When Gaara was defeated, the body just turned to sand and went away.
So only the Kyuubi's chakra is sealed within Naruto. That's what I think.