All Hallows Trick by Leigh Kelsey

Four months ago, I was a normal girl. Now I’m a monster.
I knew Ford’s End would ruin me, but I never thought it would give me fur, horns, and the mindless urge to kill everyone in my path—even my husbands. Death. Misery. Torment.
And when a sweet, deranged madman rescues us from an attack… I can’t help but wonder if there are four men at risk of being slaughtered by my monster.
My only hope of staying human is an antidote we stole from the twisted lab in the woods. But there are only five vials left, and I’m not the only one who needs them. Time is running out, and Death’s domain is fading all around us, robbing my husbands of the strength we need to fight Nightmare.
She’s more determined than ever to kill us. And we’ll never see her cruellest trick coming.