Cursed by Darkness — Anna Sanders

Winx is a daevor: a demon who can coerce people into killing themselves. After using her powers to avenge her sister's death, she's sentenced to have her wings severed and serve as a soldier. But Winx refuses to play by the rules. She goes into hiding at a BDSM club in Los Angeles where nobody would think to look for a deadly daevor. Keaton's friends and family are under attack by savages-people who arise from death as soulless monsters. Winx is the only one with the power to defeat them, and Keaton is determined to harness her dark powers... no matter what it takes.