It could make you think about your own journey of growth and the obstacles you've overcome. Maybe the determination of the characters in the story mirrors your own when you strive for something you really want.
Often, authors combine the powers and skills of Naruto characters with the dragons from How to Train Your Dragon to create unique storylines. Maybe a ninja discovers a hidden dragon village and forms bonds with the creatures.
Honestly, there's not much of a direct relation. Maybe you could look at it from a perspective of fantastical creatures and spectacle, but even then, it's a loose connection at best.
It might introduce new elements or perspectives not present in the original. Fanfictions often take creative liberties to offer unique takes on the source material.
Yoda would probably start by teaching Naruto about self - control and focus, which are key aspects of Jedi training. He might have Naruto meditate to better sense and control his chakra.
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.
First, you need to have a clear idea of the story you want to tell within the HTTYD 3 universe. Then, focus on developing interesting characters and an engaging plot.