Diamondeye's story doesn't hold up. He claims he can heal people. He also claim he can't ressurect people nor stop them at the brink of the death. What use then is his "ability"? There are noone who've turned up wounded or who could otherwise have gotten help from a healer. The possiblity of a vengful spirit looking to get rid of the people responsible for it's death rather than healing itself (How is that even possible? If you are dead you can't come back by yourself?) seems much more likely.