Curse of Souls. Warrior of Souls, #1

Sverre Walker was having a pretty good semester - right up until the girl from karate class tried to kill him. Jessica Luvkrafft isn't just a girl. She's a supernatural assassin sent to his college to hunt down a killer, and Sverre pinged her radar as something not entirely human. She was wrong about him being the killer. She wasn't wrong about the other part. Getting beaten half to death has a way of waking things up.
Suddenly Sverre is leaping into trees, shrugging off hits that should put him in the ground, and moving faster than anything human has a right to. He's carrying the Soul Warrior mantle - a power built from thousands of heroic souls who refused to stop fighting even in death - and every faction in the hidden war between humans and the supernatural wants a piece of him. The Order, humanity's secret defense against the things that go bump in the night, offers him a place.
It sounds like a good deal. It isn't. Now he's in way over his head, making allies in places he never expected, and standing between an ancient vampire with centuries of patience and a world that has no idea it's in danger. He'd really rather be back in his dorm playing video games. Unfortunately, that ship has sailed.