How to Train Your Dragon

Backstory: You come from a family that has always lived among dragons. Your ancestor was the conqueror of all dragons, known as the Dragon Emperor. However, your parents passed away. When you turned 15, you took flight on your dragon, Triple Strike—a beast with three intertwining tails that deliver a powerful poisonous blow, possessing strength equal to or perhaps slightly greater than Toothless. During one of your flights, you passed near Berk, where you were captured by Stoick (the chief of Berk). He tied you up and placed you under guard, along with your dragon.

At that same time, Stoick's son, Hiccup, shot down a Night Fury. Shortly after, he was spotted by a Monstrous Nightmare. Hiccup ran and hid behind a wooden pole, but the dragon fired a blast, setting the pole ablaze; Hiccup was saved by his father, Stoick. The next day, Hiccup went searching for the dragon. After a long time, he found it, but he couldn't bring himself to kill it and set it free by cutting the ropes. However, the Night Fury couldn't fly because Hiccup had injured its tail.

All the villagers and Stoick set off to find the Dragon's Nest, except for Gobber, who stayed behind to train the recruits (among them were Fishlegs, Astrid, the twins Ruffnut and Tuffnut, Snotlout, and Hiccup himself). At first, Hiccup struggled completely with the training, but once he tamed the Night Fury and named him Toothless, he began training with him and started handling the dragons—not through physical strength, but through understanding.

During the penultimate battle, everyone had returned and was watching the training so the elder could make a choice. You were also watching, realizing that Hiccup had tamed a dragon. After the training, the elder made the decision: Hiccup was supposed to kill a dragon. But a day prior, Astrid had followed him, and in the end, Hiccup took her for a ride on Toothless, and they found the Nest.

The day arrived, but Hiccup threw away his weapon and shield, declaring that he was not like them. He attempted to tame the Monstrous Nightmare in front of everyone, but Stoick struck the dragon with his hammer. Terrified by the loud noise, the dragon attacked.

(I don't know what else to write, so please continue on your own. Don't forget that you are observing this and can help him.)