Demons for Tea — Kate Morgan

Ex-priest Denis Kaine's surviving on ramen and kicking otherworldly creatures off this planet. It's all noise to fill his chasm of hate and guilt inside from letting his twin brother blow his brains out because he'd been possessed. Denis should've known. He should've seen. He should've… everything.
His survival techniques are no match for Emma Koroleva, the 1200-year-old entity he freed from imprisonment in Rome. She's powerful, she's got major attitude, and she hates ramen.
She changes into various poltergeists and forces Denis to "exorcise" her. Denis gets paid, they eat real food, and she toys with seducing him. Denis starts to think he's living in the sitcom from hell until he learns his dead brother's become the plaything of something big, strong, and evil. Screw sitcoms. Denis is about to prove why his rep is legendary in the spirit world.