yep and he had to say he would become the devil to save Manna because he needed Shu to kill him and if had given Shu any cause to feel his motives were anything other then selfish Shu would of hestitated to strike him as we seen he became instantly concerned after he attacked Gai in which Gai softened his words and told Shu to keep being himself and to save Inori he just wanted to Shu to live and be happy but saving Inori was not in the cards.
It's just fine throughout for me. My thoughts are about the same as kanna, preferred the second half of the series. Not much strong points for this series but the ED 1 is <3.