Twice born, once raised

What would happen if at the young age of 8 Hiccup was kidnapped by dragons and turned into a young Nightfury, then 5 years later at the age of 13 went back to Berk? Well, I cant tell you that! You'll have to read and find out wont you. Rated T because I worry too much. UNDERGOING REWRITE FROM 21/12/2015