I am a big fan of Naruto, and assuming the brothers make simillar manga, I have been looking into this. But I am unsure about the main theme. Is the story Good vs. Evil, where the Evil is the main heroes and the Good is the enemy? All I know is the main character has Satan in him, and there are fights between Angels and Demons. Or is it like Naruto where Naruto has an evil creature inside of him, uses his power, but he himself is a good guy who fights evil?