The Blood Masquerade - The Lost Ones Trilogy, #2

The carousel is destroyed. The Collector is defeated. The world of the dead has been opened. When Makin Riley went down into the world of the dead with his friends, Frankie and Marcus, they hoped to rescue his little brother, Stevie's spirit and bring him back to life. They neverintended to unleash something evil into the world of the living. Now the living must come together, both human and fey, in order to figure out a way to return the dead back to their world.
But a rogue elf named Echron sees this as an opportunity to get revenge on the courts that banished him. Book 2 of The Lost Ones Trilogy