Sunroper by Natalie J. Damschroder
Marley Canton is done being a victim. A year and a half has passed since she discovered her ability to nullify power in those who aren't supposed to have it. She's now on a quest not only to stop the brats who've become addicted to goddess power, but also to find the source of their addiction.
Like Marley, Gage Samargo is tracking down the goddess who went rogue decades ago. Insane with too much power from the sun, she's selling that energy to Gage's younger brother and his friends, who are no longer content to come into power naturally. While they work to find a way to neutralize the goddess, Marley discovers that every time she nullifies someone, she takes on some of the goddess's insanity.
Gage falls for Marley's sharp wit and intense desire to right wrongs. But once he discovers she's turning into her enemy, is it too late to back away?