I thought sage mode allows the user to utilize the ambient natural energy them thus replenishes his or her depleting chakra? It sounds like a healing technique in disguise, how did he get exhausted so easily? I also wonder whether sage mode will enhance naruto's control of 9tail's power, if so, it would seem that naruto can further better sage mode by using a combination of spiritual energy + physical energy + natural energy + demonic energy (9tails) = super awesome technique?
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