I KNEW it would be Lucifer. He's the coolest. He's an angel you know. Lucifer Morningstar, the brightest of all angels. He's been sadly maligned.
FYI all magic is neutral and it's the actions in using it that are dark or light
I really love the premise of the story and the way that there are lots of different strands... Jayden, Lucifer's son: Arthur with his dreams of being an angel: the sickness. I figure they are all connected and look forward to seeing how.
As a matter of criticism I would work on the dialogue.