My Balls/WMG

Hell is populated entirely with female devils because female angels all fall
Michael is ancient and has been an angel forever. The only female angel we meet is Nina in the extras. She somehow rationalizes giving a kid a handjob and outright trying to have sex, then convinces the girl who likes him to try to have sex with him. She gets frustrated and snippy easily. That halo received a good coating of tarnish pretty fast. If she sticks at the job for much longer she'll eventually say "ah, fuck it" and go party downstairs.

The entire series is one Batman Gambit by God
The end result of this series is that two demons, one of them Satan no less, are redeemed and turned back to the light. No demon has ever been redeemed before Hell is shaken to its very foundations with an emotion that has not been felt there ever before: hope via love. They finally have hope that they can survive and return to Heaven.

Now if Michael's original plan was just sealing Emmaniel into the ball of holding then nothing would have happened, but the oldest most powerful angel on his most important mission in at least 2000 years messes up just from a tiny distraction from a mortal? Seems unlikely unless a divine hand took a role to ensure that a man whom Elyse, who is chosen as Emmaniel's back up despite her complete lack of experience, can fall in love with. God foresaw that this is the one and only chance that the demons of hell could possible have at redemption and like the parable of the lost sheep he left the rest of the flock to try and bring them back.

As 1 Corinthians 13:13 states "And so there remain Faith, Hope, Love--these three; and of these the greatest is Love." God deliberately chooses for this to be the method of redemption because it is not only the greatest and most powerful of the emotions, but as 1 John 4:16 states "... God is love. Whoever lives in love lives in God, and God in him." In the end, God does not even break His word as He allows the demons to come back to Earth become human and have their descendants live in the world. He Took a Third Option between the demons' total damnation for all eternity and humanity's destruction in Armageddon.