Well, perhaps in this fanfiction, Hiccup uses his unique bond with dragons to gradually gain the trust of the Red Death. He might start by understanding its behavior and needs, and then through a series of adventures and challenges, he manages to tame it. Maybe he discovers a way to communicate with the Red Death that no one else has thought of before.
In this fanfiction, Hiccup is the central character as he takes on the task of taming the Red Death. Astrid could also be involved. She might be skeptical at first but later see the value in Hiccup's attempt. And the Red Death is the key character that the story focuses on taming. There could also be other Vikings in the background who either oppose Hiccup's idea or are in awe of his courage to take on such a dangerous dragon.
She might be devastated. Bella could go into a state of shock initially. Then, she might feel a deep sense of loss and loneliness. She could also be filled with anger towards the cause of her father's death.
Hiccup's death in the fanfic could be a shock and create a lot of tension. It might force the other characters to step up and take on new roles, or it could even serve as a turning point for the entire story's theme and message.
It could be that the situation around his death had some ironic elements. Like he was always so careful about one thing, say not getting wet in the rain, but on his last day, he ended up in a big puddle and it just makes for a strange and funny story to tell later. It's not making light of his death, but finding the odd and humorous moments in the events leading up to it.
Often, in such fanfictions, Hiccup might die in a heroic battle against an ancient evil that threatens the entire dragon world. This could lead to a powerful emotional arc for the other characters.
It can have a very significant impact. Hiccup's death might trigger emotional responses from other characters, leading to new plot developments and character growth.
Well, Hiccup is very resourceful. He could use the environment around him to his advantage. If he is locked in a place, he might find a weak spot in the structure, like a loose board or a hole in the wall. And he could call for Toothless secretly. Toothless, being highly intelligent, could find Hiccup and rescue him. Also, Hiccup could befriend some of Viggo's minions and convince them to help him escape.
Toothless is the most likely one. Their bond is so strong that Toothless would sense Hiccup's distress and come to his rescue. He could fly into Drago's hideout and cause chaos to free Hiccup.