LYCOS RETRIEVER 
Naruto: Chakra
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Naruto and Yamato arrived to help Choji, Ino, and Kakashi battle Kakuzu, who so far has been revealed to be more than a match for the team. Naruto challanges Kakuzu himself and reveals his new jutsu, the Wind Release: Rasengan, and its special ability, the Wind Release: Rasenshuriken. After one failed attempt, Naruto managed to get behind Kakuzu, trapping him in the incredable vortex of wind, tearing Kakuzu apart. When Shikamaru arrived to tell them Hidan was delt with, they return to Konoha. Upon their return, Naruto needed to be hospitalized due to injuries to the arm he used the Rasenshuriken in. Tsunade told Kakashi that the Rasenshuriken caused cellular damage to cells in his arms which could render him unable to use chakra, and has since forbidden the use of the technique.
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If Naruto musters enough of the fox's chakra, a chakra shield is summoned, dubbed the "demon fox's cloak" in the anime. This shield is capable of acting on its own as a separate entity, making it difficult to predict Naruto's movements. The shield created by the demon fox's chakra is perhaps the most versatile defense seen in the series, since it is impervious to almost any attack. The shield can ... stretch and skew to many sizes and lengths, allowing Naruto to attack opponents from a distance. Additionally, Naruto can use it to create waves of concentrated chakra to repel opponents. In Naruto's four-tailed state, the chakra shield is intense enough to burn others and act as a potent poison.
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The demon fox's chakra usually comes to Naruto during life threatening or other stressful situations, given to him by the fox itself to ensure its survival. Naruto eventually learns to contact the fox and demand some of its chakra, which it seems to comply to out of amusement. The reason Naruto is able to access its chakra is because of the unique way in which it was sealed. Though the fox remains trapped within Naruto, its chakra can leak out through the seal and mix with Naruto's. The fox's near-limitless supply of chakra becomes an invaluable weapon for Naruto, often turning the tide of a difficult battle in his favor. The fox chakra increases every aspect of Naruto's physiology, making him a nearly unstoppable force.
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The fox chakra enhances every aspect of Naruto's physiology, making him a nearly unstoppable force. His speed and strength increase far beyond that of most ninja, as does his healing rate, allowing him to regenerate even major wounds in a few seconds. His stamina is ... increased beyond its normal level, allowing him to fight without tiring. Because the chakra holding back the fox's chakra is gone, Naruto also gains the ability to mold the chakra to a much finer degree, allowing one-handed Rasengans.
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