The Demon's Due: An Enemies-to-Lovers Urban Fantasy. Bedeviled AF, #5

Magic has a price, and Aviva's running out of ways to pay. When an ancient healing ritual goes nuclear and vampires start short-circuiting, the supernatural world begins unraveling faster than you can say "apocalypse now." Aviva isn't just investigating a disaster-she's living in the blast zone. Meantime, with demon magic threatening her boyfriend's life, Aviva makes a desperate choice: she forges a magic bond with him.
Nice idea. Too bad it complicates everything. Now tethered to each other and racing against time, they must find a way to contain the chaos unleashed by the ritual-assuming their connection doesn't destroy them first. Time to fight fire with fire. Literally. To save the world, Aviva must embrace both sides of herself: the dedicated operative and the demon who's done playing nice. Enter Cherry Bomb.
The world better brace for impact. Featuring a smart, determined heroine, a banter-fueled vampire romance, and high-stakes supernatural intrigue, the final chapter of this wickedly addictive urban fantasy will keep you reading way past bedtime. Read the complete series now.