Last edited by UChessmaster; Sun, 10-13-2013 at 06:20 PM.
You cannot hope to build a better world without improving the individuals. To that end each of us must work for his own improvement, and at the same time share a general responsibility for all humanity, our particular duty being to aid those to whom we think we can be most useful. -Marie Curie
One offensive technique maybe. But he's been doing a lot of turning into liquid and regeneration as well. I assume all of that takes chakra.
They were very explicit. With Naruto at least, Sage Mode only lasts about 5 minutes. And if he uses powerful techniques like the double Rasengan or the Rasenshuriken, it runs out even faster.