Zabuza and Kakashi sense the power and stop.Kakashi realizes what and who is making the chakra. His eyes widden in terror.Zabuza is still at a lost. Kakashi remembers that night that Iruka, Naruot and so many others lost families and friends....the night the nine tailed fox demon came to Leaf village. and was sealed inside his body by the third Hokage. That was it naruto had some how broke the seal on his tummy to keep the fox at bay within his body for the past twelve years.