The Monarchs by Kass Morgan

In this thrilling conclusion to best-selling authors Kass Morgan and Danielle Paige’s The Ravens, the sorority witches are tested when a rival threatens to usurp their place on campus and the forces of hell come knocking on their door.

The sorority girls at Kappa Rho Nu—the Ravens—are determined to restore balance to the world. After destroying an ancient talisman and barely saving their sorority in the process, they’ll go to any lengths to keep their secret as Westerly’s most powerful coven of witches.
Scarlett Winter, a legacy Raven, has finally gotten what she’s always wanted: the Kappa Rho Nu presidency. After the disaster that killed the sorority’s last president, Scarlett is determined that no sister will fall under the sway of wicked magic ever again. But the powers of the presidency have their own pitfalls—and Scarlett has big shoes to fill.
Vivi Devereaux, a freshman, finally knows what it feels like to belong. For the first time ever, she’s got it all: her Kappa Rho Nu sisters and a sweet (and hot) boyfriend. When Scarlett assigns Vivi the coveted role of social chair, Vivi is determined to live up to her Big’s expectations—even if that means dabbling in a new form of magic.
Unbeknownst to the Ravens, new rivals and ancient evils lurk on Westerly’s campus. With Kappa Rho Nu’s future on their shoulders and their pasts still haunting them, will Scarlett and Vivi be able to save their sisterhood once again?