Caedes(Book#1 in Hybrid series)

Saint is a half angel and half devil from heaven. He came to Earth after loosing his parents, who were murdered by a demon, and tried to fit in as a human. Years later after a demon attack the heavens put up barriers to separate Heaven, Earth, and Hell. Leaving demons on Hell hungry for vengeance.

But when the barriers breaks, demons are threatening the lands and without alliance neither the devils, angels, or humans will make it out alive.

So, five strangers are united by five stones that grant them powerful abilities to defeat the demons, Saint being one of them. Then there's Rhea an angel who has a dark secret. Damon a devil who practices dark magic. Hera a half angel half devil like Saint. And Larissa a human with a rebellious side.