Our protagonist, Ace Dante, has been kicked out of the Underworld (the Egyption one) and cursed to walk the earth forever. He is an investigative detective or sorts. His work "partner" is a demon named Shukra, another part of the curse which has bound these two antagonists to walk their paths together.
Ace is bitter, snarky, and trapped to do the God Osirus' evil bidding. He feels the guilt of past sins, and despairs of being better. Sometimes the bad guys win.
If you like Jim Butcher or Kevin Hearne you'll probably like Pippa Dacosta, these books have a similar feel to them.