Juno Obsidias

ジュノー ・オブシディアス Juno Obushidiasu, Prince Juno, Sire
Son of the King he idolized Exa as a harbinger of peace who would aid his father in exterminating the demons. However when he met Exa and found out he was a pacifist because he refused to kill two humanoid monsters the Prince was severely disappointed. After he is spared by one of the two monsters that Exa saved however he converts to Exas philosophy and provides to be a valuable ally. However it is he who sends his aide to warn Exa of his suspicions that Sheila is the real Demon Queen. From Wikipedia