I'm divided on this book. It was really hard to get in to. The mixture of Chinese and Japanese lore and names felt off. It felt as if the writer just tossed both on one big heap and didn't care about accuracy and sensitivities. Or maybe that is just me. But that made it difficult for me to read and decypher which culture he was going for.
However, as the plot progressed, it slowly sucked me in. It didn't read like 'Ninja Scroll' as some people say. It felt like 'Mortal Kombat' to me. The constant duels, using the powers. That doesn't make it bad (or good), but did give it a fractured feel.
But... despite that, it kept drawing me in, and the ending was very original and very well executed. Marvelous twist.
So... the beginning and first third of the book: 2 stars out of 5. Second third: 3 stars. Last third: solid 4 stars.