Everwhereatonce
Hiccup didn't lose his leg, instead he got massive burn scars that clearly came from an explosion, and Hiccup is blind in his right eye. The dragon riders act nice but secretly hate him. The hunters are good. Viggo doesn't know of Hiccup's past until later. Stoick never truly accepted Hiccup as his son, and Hiccup knows it. Also Hiccup gains elemental powers from taking in vast amounts of said elements.
How will everyone react when faced with Hiccup's biggest secret? Will he find comfort in the people who were supposed to hate him most? Or will he be lost to bitter goodbyes and self loathing?