Light Yagami is a human but he can turn the death note into a scythe his red eyes are the shinigami eyes Light represents the devil in wanting to be a god and creating a new world using his death note even though he’s still just a human. After discovering the Death Note, he decides to use it to rid the world of criminals. His killings are eventually labelled by the people living in Japan as the work of "Kira." He has inner monologues, with the intent to see if someone wants to see if he's Kira