Hey, so sorry to disturb your story, but I wanted to share an idea with ya, for the next one, of course if you think is interasting.
So I was thinking that of a crossovwr of HTTYD with Assassins Creed Odissey, its story essencially, where Hiccup has a older brother, who sis only a year older than him, and both are descendents from the Isu civilization, being a target to an ancient society, as the Cult of Cosmos was in the game, in thi story Hiccup is taken away by this society and grows like Deimos did in the story of the game, but eventually he was saved, thanks of tbe efforts of his mother, father, Astrid and Toothless. See if you like the idea, please. See ya!