«Magic Betrayed» by Elizabeth Kirke

Never again must another Arcanist rise…
They say it took one hundred magical beings to defeat the first Arcanist. Great care was taken to ensure the secret to his malevolent power died with him. Now the brutal reign of the Arcanist has become little more than a scary bedtime story. And yet, the descendants of his loyal followers are sworn to find a way to bestow his dark magic upon another. If they succeed, they’ll unleash a new terror upon an unsuspecting world.
Now, magics are vanishing without a trace. It’s up to Jen Maddox, a young witch working for the Magical Enforcement and Secrecy Agency, to find out why. Jen soon learns that those responsible for the disappearances will do whatever it takes to stop her investigation… including using an ancient, forbidden magic. With each clue uncovered the mystery grows, pointing towards one unthinkable scenario — an Arcanist is once again rising.
Magic Betrayed is Book Four in the Urban Fantasy series, More than Magic, featuring witches, vampires, werewolves, and more. If you like your magic mixed with a little mystery and sweet romance, dive into your copy today. While it is book four, it takes place five years after the original trilogy and can be enjoyed first. The original trilogy is also available on audiobook.