One in a million

Pietro had always thought he was a normal viking boy. Normal training, normal house, normal almost getting himself killed when dragons attack you get it. Well....I did say had.
Little does he know he was born with a terrible curse. Every full moon (depending if it's a blood moon or something like that) he transforms into a beautiful, mysterious, elegant, easily-terrified Light Fury. And the only thing that is sort of giving it away when he tries to keep it a secret is a tatoo of a light fury eye on his arm. Will he be able to keep this curse in the drafts? Or will it be unraveled?