Great show. Very action filled, if you know the history about the one of greatest swordsman of all time in Japan, you'll love the main character. His name is Miyamoto Musashi. Great animations, a lot of comradery. A decent amount of humor when the gang is all there. Good amount of strategy on both ends. Lots of character death and quickly too. Also hold onto your grass because it takes the seriousness out of a heartbreaking and brutal scene. Which I don't mind, gave me a good chuckle. There was a lot of character development, some scenes could've been written differently or added that would've made it better (Mainly near and at the end).
SMALL SPOILERS AHEAD RELATED TO WRITING MESS UPS NEAR END, I WILL KEEP VAGUE, BUT READ AHEAD AT YOUR OWN RISK!:
A character who dies near the end as a "Martyr" could've been avoided if they injured themselves less. The very final battle with Miyamoto and his opponent should've been animated as well as shown. They should've also shown even a short glimpse of his life after or even a small talk with the head monk, as well as reuniting with his friend.