Peregrine Serendipity

The son of King Francois the Second, Elrion Xerneum, is born without sorcery, necromancy, or thaumaturgy, and so he is exiled to the Dome of Death, a pile of people who don't possess magical powers. Unlike others, Rius is instead sent to be tortured by a couple until death so he doesn't instantly die in the Dome of Death.