Well, Astrid could potentially make Hiccup mad in fanfiction too. For instance, if she goes against Hiccup's orders during a crucial mission because she has her own ideas and doesn't trust Hiccup's plan. Also, the dragon hunters in fanfiction are always a source of Hiccup's anger. They are constantly trying to capture or harm dragons, and Hiccup, being the dragon lover he is, would get extremely angry at their actions. And sometimes, even Toothless, if he's written in a way that he's being overly stubborn and not listening to Hiccup, could cause Hiccup to get mad.
The elders of Berk can be the ones to make Hiccup mad. They might oppose his new -fangled ideas about dragons and try to enforce the old ways. They could undermine his authority in front of the whole village, which would definitely make Hiccup angry. And then there are those jealous villagers who might spread false rumors about Hiccup's relationship with dragons. This could make Hiccup mad as it could put his hard - earned peace at risk.
For Kakashi, a character like Naruto could potentially cause jealousy in some fanfictions. Since Naruto and Sakura are very close friends, if Sakura spends a lot of time with Naruto on a mission or training, Kakashi might feel a twinge of jealousy. He might wonder if there are deeper feelings between them. As for Sakura, a new female sensei in the village could make her jealous. If this sensei is very attractive and Kakashi seems to respect her a great deal, Sakura could start to feel envious.
Obviously, Hiccup and Toothless would be central characters. Astrid might also be there, as she is an important part of Hiccup's life. Other dragon characters like Stormfly, Hookfang and the rest of the dragon riders' dragons would likely be involved too.
There could be some new characters introduced as well. Maybe a mysterious dragon rider from a far - off land who also has the ability to talk to dragons. This character could either be an ally or an antagonist to Hiccup, depending on their motives. Or perhaps an old dragon trainer who has long - forgotten secrets about the dragons' language that Hiccup has to discover.
Astrid is likely to be one of the main characters to interact with Hiccup. She might be initially very confused or even a bit jealous depending on how she perceives Hiccup's new form. Stoick, Hiccup's father, would also have significant interactions. He would probably be shocked at first but then try to support his child in this strange situation. And of course, Toothless. Their bond is so strong that Toothless would surely be involved, perhaps trying to understand what has happened to his rider.
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.
Well, obviously Hiccup would be one of the main characters. His character is central to the whole concept of refusing to kill dragons. Astrid could also be a main character. She might initially be on the side of the traditional view of killing dragons but gradually come to understand and support Hiccup's stance. Stoick, Hiccup's father, would be an important character as well. His position as the chief and his traditional beliefs would create a lot of conflict with Hiccup's new ideas. And of course, the dragons themselves, like Toothless, could be considered main characters in a sense. They are the ones that Hiccup is trying to protect and coexist with.
Another possibility is a jealous rival. Maybe there's someone who is jealous of Gohan's power or his relationship with certain characters. This rival could do things to annoy Gohan and push him to the edge of his temper.
A new player on an opposing team could be the cause. This new player might be overly cocky and disrespectful towards Kuroko during a game. They could constantly taunt him about his lack of presence, which finally gets on Kuroko's nerves and makes him mad.
It could be Vegeta. Maybe Vegeta does something really underhanded like stealing Goku's senzu beans or trying to take all the credit for a victory that Goku also contributed to. Goku, being a fair - minded person, would get angry at such behavior.
One of his friends could be the cause, accidentally. Maybe a friend makes a deal with a shady character without realizing the consequences. This deal ends up putting everyone in danger, and Yami gets mad at his friend's naivete and the mess they've created.