Eternal Ruin by Tigest Girma

Like all ruinous things, he came from the abyss.

Kidan Adane has finally embraced her darkness. She's killed without remorse, lied, and broken Uxlay University's most sacred law by inviting elusive rogue vampires into Uxlay and binding herself to their depraved leader, Samson.

Trapped with a violently unstable vampire and reeling from her sister's return, Kidan wields her anger like a weapon. She vows to master her house and protect the sacred artifact hidden inside, even if it means forging an alliance with Susenyos Sagad.

Kidan knows no soul at Uxlay is trustworthy - least of all Susenyos. The lines of their loathing and lust may blur, but the quest for power rules them both. And neither is willing to surrender. 

As devastating secrets resurface from the past, Kidan and her sister, June, must finally confront one another and take their rightful places in the looming war.