Superhero Proving Grounds

All angels are born pure from sin, temptations, malice, and evil. They are, by their divine nature, embodiment of innocence and good, acting as exemplars of a perfection that humans, while they cannot truly reach it, can at least aspire to become. However, this innocence comes at a price: angels are trusting and kind, and thus can easily be manipulated. And through these manipulations, one may even corrupt an angel, and let it fall from grace.

Such a thing happened to Azael. A succubus charmed the once-pristine angel, indulging his love of fighting and perversing it, and him by the same process. He became a fallen angel, stripped of his divine powers and left open and helpless against the influence of Hell and it's spawns. For a while, he became nothing more than a toy for demons, such disgraced angels were extremely rare, and thus he became a highly praised toy to torment. He was commonly traded between succubus queens, archdemons and Hellish lords and ladies to be humiliated, beaten senseless and worse, until one day, an army of angels led an assault on Hell, liberating the fallen angel in the wake if their assault.

While he was brought back to Heaven, questions remained as to his loyalty, and as whether or not he could reach a state of grace ever again. However, Michael the Archangel, saw in him something that most angel lacked: he knew evil, knew it's dangerous influence, how it could corrupt even the most innocent souls, and thus could sense and see it where any other angel would be too trusting and kind to ever suspect anything. More than that, despite having been corrupted, he still resisted the Hellish influences and manipulations, and never became a demon himself. And thus, Michael chose to let him rejoin Heaven, regain his divine nature, but not his innocence.

Azael was this given much more leeway than is usually given to angels. His love of fighting, his arrogance and pride, his brash and scrappy temperament were tolerated to an extent, but in exchange, he became a watchdog, ever looking for the corrupting influence of Hell and it's minions, while occasionally ruffling the feathers of his fellow angel with his abnormal behaviour and his tainted nature.

Powers:
Flight (I have wings, duh!), Healing, Enhanced strength, Purification