Endinq question...
spoiler
In the very last scene we see our main character starting to weep. Why do you think that is? Is it because he felt remorse for killing such a well matched opponent? Maybe he saw in him, a younger version of himself... striving for fame and that now he has cut his life short and he shall never evolve on his own to be an even greater samurai.
Or maybe he's relieved to have survived fearing that this time he had met his superior?
Or i suppose a little bit of everything. After all he's been through, surviving this victory and all the rest before it along with his changed philosophy, his regrets, the emotional weight of everything finally manages to crack through his tough facade.