In Vendetta House (The Vendetta Series #1)
There is a mansion in the middle of nowhere called Vendetta House, tasked with the sole purpose of taking in kids like Ariel: Cambions, the offspring of demons.
The day that Ariel turns eighteen, she not only discovers her abilities as a Cambion, but she is taken to Vendetta House, kicking and screaming. Gifted with telekinesis, telepathy, and elemental control, demon-bloods are removed from society for their own good, or so Ariel is told.
But Ariel has bigger problems than her hostage situation. An abandoned section of Vendetta House hosts hundreds of dead spirits, ghostly remnants that only Ariel and another strange boy can see. Since her arrival, the dead numbers have been rising, and coincidentally, kids within the House are going missing too. With the help of her new friends, Ariel must uncover the secrets of Vendetta House, or before they know it, they may just disappear too.