A major theme is power. Harry as a dragon often has new and different powers compared to when he was a wizard. There's also the theme of isolation. He may feel alone in his new form, not fully belonging to the wizard or dragon world. In many of these fanfictions, Harry also has to face challenges related to his identity. Is he still Harry Potter, the boy - wizard, or is he now something entirely new?
In the fanfiction, Harry might be cursed to transform into a dragon periodically. He then has to figure out how to control this new form. He could meet other magical creatures that are either scared of him or intrigued by his dragon form. He might also find that his dragon form gives him unique powers that he didn't have as a human wizard, like the ability to fly faster or breathe a more powerful type of fire.
Well, perhaps Harry stumbles upon an ancient book about dragon riding in the restricted section of the library. As he reads it, he's drawn into a world of dragon riders. He then meets a mysterious figure who offers to teach him the ways of dragon riding. Harry embarks on this new adventure, facing challenges like learning to communicate with the dragon and mastering the art of flying on its back. Along the way, he makes new friends among other dragon riders and they all fight against a common enemy that threatens the existence of both the wizarding world and the dragon habitats.
There could be a group of pure - blood wizards who believe that dragons are beneath them and that Harry is tainting the wizarding world by associating with them. They would try to stop Harry from his dragon - related activities, and they might use underhanded tactics like casting spells on him or trying to get him expelled from Hogwarts.
It could be a dark wizard who wants to control the dragons for his own evil purposes. He might see Harry as a threat because Harry is forming a bond with the dragons and teaching them to resist dark magic.
A great 'harry becomes a dragon fanfiction' is 'Harry's Dragon Ascent'. In this story, Harry is turned into a dragon by a powerful spell. His dragon form is majestic and has unique abilities. The story follows his journey as he tries to figure out how to change back. Along the way, he forms a bond with a group of magical creatures who help him understand his new form better. There are also some really exciting battles in this fanfiction where Harry uses his dragon powers to fight off dark forces.
If Harry Potter becomes a dragon rider in fanfiction, he could explore new magical places. Dragons can fly to remote areas. He might discover hidden magical lands or ancient magic that could help him in his fight against the dark forces. Maybe he'd find a new kind of magic that could defeat Voldemort once and for all.
One idea could be that Tsukune discovers a hidden dragon lair. Inside, he finds an ancient spell that accidentally transforms him into a dragon. As a dragon, he has to learn to control his new powers like flying and breathing fire. He might also face challenges from other magical creatures who see him as a threat.
Link's character would change drastically. As a dragon, he'd be more powerful physically but might struggle with his sense of self. He'd have to learn to control his new instincts. For example, his natural inclination as a dragon might be to hoard treasure, but his human values would conflict with that. This internal struggle could be a major part of his character development.
One idea could be that Link is cursed by an evil sorcerer to turn into a dragon. In the fanfiction, he might initially struggle with his new form, not understanding how to fly or use his dragon powers. As the story progresses, he could discover that his dragon form has unique abilities like breathing fire to defeat enemies he couldn't before. He might also have to find a way to break the curse while still in dragon form, perhaps by finding a magical artifact or by performing a heroic deed.