Vicious

Victor and Eli started out as college roommates--brilliant, arrogant, lonely boys who recognized the same sharpness and ambition in each other. In their senior year, a shared research interest in adrenaline, near-death experiences, and seemingly supernatural events reveals an intriguing hidden possibility: that under the right conditions, someone could actually gain extraordinary abilities. But when their thesis inevitably moves from the academic to the experimental, things go horribly wrong.

Ten years later, Victor is breaking out of prison, determined to catch up to his old friend (now foe), aided by a young girl whose reserved nature obscures a stunning ability. Eli is on a mission to eradicate every other superpowered person he can find--aside from his own sidekick, an enigmatic woman with an unbreakable will. Armed with terrible power on both sides, spurred onward by the memory of betrayal and desperate longings, the archnemeses have set a course for revenge--but who will be left alive at the end?

V. E. Schwab's Vicious is a riveting investigation on the nature of loyalty, the possibility of redemption, and an exploration of our darkest, most thrilling selves.

This description comes from the publisher. Vicious is the first book in the Vicious series.