In the HTTYD fanfiction where Hiccup turns into a Night Fury, how would his relationship with Toothless change?

Well, it would become a more equal relationship at first. Since Hiccup is now a dragon, he can understand Toothless on a whole new level. They might compete in dragon activities like flying races or hunting together. However, Toothless might also be a bit confused at first, not sure how to act around his once - human friend who is now a dragon.

His relationship with Toothless would change drastically. Instead of being the rider, he becomes like a little sibling or a young apprentice to Toothless. Toothless would have to be more protective and patient with Hiccup.

His relationship with Toothless would be very different. Toothless might be more protective of him in his new form, as if sensing that Hiccup is more vulnerable as a female Night Fury. And Hiccup would have to communicate with Toothless in new ways, perhaps using more body language that is typical of female Night Furies.

If Hiccup had powers, their bond could become even stronger. For example, if Hiccup could share his thoughts directly with Toothless using his new power, they would be able to coordinate in battles more seamlessly. Toothless might also become more protective of Hiccup, knowing that his rider now has powers that could attract unwanted attention. They could communicate in ways that no other dragon - rider pair could, like sharing memories or feelings instantaneously.

One possible plot could be that Hiccup, after some magical or scientific experiment gone wrong, transforms into a Night Fury. At first, he's terrified and confused. His dragon Toothless tries to help him understand his new form. Hiccup then discovers new abilities like enhanced flying speed and the power to shoot more powerful blasts. The other Vikings are initially scared of him, but he eventually shows them that he's still the same Hiccup inside, just in a different form. And he uses his new form to protect the village from a greater threat that normal dragons and Vikings couldn't handle alone.

There would be a shift in their dynamic as they prepare for a family. Hiccup, who is used to being adventurous, would have to focus more on home and stability. Astrid, while still strong - willed, would become more nurturing. They would need to find a new balance in their relationship, between their old selves and their new roles as parents - to - be.

One idea could be that Hiccup wakes up one day to find himself in the body of a female Night Fury. At first, he's completely confused and tries to figure out how to control this new form. He might struggle with flying at first, but as he gets used to it, he discovers new abilities that come with being a female Night Fury, like a different type of sonic blast. The other dragons in the village are initially startled but then start to accept him in this new form.

If Hiccup is under Pitch Black's control, it would be a huge shift in his relationship with Toothless. Normally, they have a deep, trusting bond. But now, Hiccup might start to command Toothless in a harsh and uncharacteristic way. Toothless would sense that something is wrong with his rider. He would try to resist Hiccup's commands at times, which would create conflict between them. Eventually, Toothless might be the key to breaking Pitch Black's control over Hiccup as he tries to reach the real Hiccup within.

A power - hungry Viking who sees Hiccup's transformation as a threat to his own authority could be the main antagonist. He might try to capture Hiccup in his Night Fury form and use him for his own evil purposes, like trying to create an army of transformed creatures.

With his human friends, it would be really tough. They might be scared of him at first. Astrid, for example, would be conflicted. She was attracted to Hiccup as a human, but now he's a dragon. She would have to overcome her fear and try to find a way to communicate with him. And Hiccup would feel isolated from his human friends, longing for the connection they once had.