How to incorporate elements of 'How to Train Your Dragon' and the Skyrim Thieves Guild into fanfiction?

You could start by imagining unique spells or magical abilities for the dragons. Maybe they can breathe fire with special effects or have the power to heal.

You could have the characters wear masks for a disguise during a secret mission or adventure.

One way could be to have Nidhogg be an ancient and mythical dragon that holds a secret key to some hidden power or treasure that the characters must discover. You could also give Nidhogg special abilities that make it stand out from the other dragons in the story.

You might consider creating a storyline where a powerful storm with lightning strikes causes chaos, and during this chaos, a mysterious force related to death itself emerges. Or perhaps have a character gain the ability to control lightning but at the risk of losing their life. Also, a quest to find a relic that can prevent the arrival of death itself could add an interesting twist.

Well, you could create a crossover world where characters from Naruto encounter the dragons and learn from them. Or give Naruto characters the ability to ride and train dragons, similar to the way they master jutsus.

It's not too complicated. You can start by imagining yourself as a character in the How to Train Your Dragon world and describe your interactions and experiences with the existing characters.

Well, think about making Zephyr baby a key element in a new adventure or quest. Maybe it has a hidden power that only reveals itself when needed. Or, you could have the other characters form a special bond with it that changes their perspectives and actions.

You could start by imagining your character having special powers or abilities similar to those of a Dragonborn. Maybe they have a unique connection to dragons that sets them apart.

Think about creating a situation where Hiccup's bond with Stormfly is tested, and Dick provides unexpected support. Or maybe have them on a quest to find a magical item that only their combined efforts can obtain.

You could start by imagining a wild encounter between Hiccup and the feral dragon. Maybe it's an unexpected meeting in a remote part of the island.