Angels, Devils, Fallen (book 1 in 'The Flightless' series)

Mage. That one troublesome angel. There always is that one in a group. The one who can't get enough thrills by simply jumping off the cliff-he just has to see if he can fly too.

Mage constantly stands at the edge, testing just how much he can get away with. And he can get away with a lot.
Naturally, one day he takes it a bit too far.

As it happens, Mage just so happened to be the Ex bodyguard of Lucifer, the king of hell himself. Mage refuses to believe his lord did anything wrong. And seeing only the good in Lucifer, he makes an attempt at helping him regain his throne. He helps Lucifer break into the city of Diamánti.
This is a story of friendship, betrayal, death, life, magic and misadventure.
Let's see who cries first.