Daigo Kagemitsu comes into the Hall of Hell and a buddhist monk tries to persuade him to return before he makes a deal with the 12 demons residing in the statues. He kills the monk and makes the deal anyway.
The story's setting is awful that the monk thanked Daigo for killing him before he loses faith in Buddha.
Picture a little baby, with its big head, no hair, and large eyes. Now, take away those eyes and leave holes behind. Now take away the ears and the nose. Take away the limbs, leaving only a torso. Now, to top it all off, take away the skin of that baby, leaving behind what looks like a tiny skull covered in blood. And that baby? It's alive. And breathing. That's what happened to Hyakkimaru. The demons left him with the barest minimum of humanity. Most people who find the baby are astonished by not only the fact that he's alive and breathing but that he is apparently running on sheer determination to live so much so that everyone can pick up on it from the midwife to the doctor who finds him.
The midwife is eaten by a mantis demon.
The graphic depictions of fresh battlefields in the war torn country.
The skin on Hyakkimaru's growing back over the exposed facial muscles, teeth and eyeballs.