Azrael is a Séraphim famous because he is a very good Fighter and killer of demon during the wars of paradise and hells. But today one of favorite god soul reincarnated so a Séraphin have a big mission and they know it as they have to protect and see how grew up that soul for God can have eyes on him all time as God have hesitation of making of that soul a futur angel in his futur death

Azrael got choosen because others seraphim are busy and it annoy him. He love war. Not that.