Archangel by Ava Martell

Speak of the Devil, and he shall appear.
Fall for an angel, and he may just lose his wings. . .
An Archangel, a witch, and the Devil himself walk into a crime scene. The punchline? They’re Heaven’s only hope.
After centuries of life, Elissa thinks she’s seen it all. But when the one angel she trusts goes missing, Elissa is forced to admit this is a new one—she’s never seen anyone abduct an angel.
With the divine out of reach, Elissa finds herself praying for infernal intervention. Better to deal with the devil you know than the angel you don’t. Luckily for her, Lucifer still haunts the City of Saints and given their history, he’s willing to help.
It would have been a match made in Hell if Michael hadn’t shown up.
Millennia have passed since they last spoke, and though Michael is on his own road to redemption, Elissa remains his biggest regret. His greatest desire is to make amends for his past, but how can Elissa and Lucifer forgive him when he can’t even forgive himself?
All the while, they stand in the shadow of a monster prowling the streets of New Orleans—a monster Elissa may have created herself.