One interesting plot idea could be that the dragons start to communicate with Hiccup in a more complex way through their listening skills. For example, they might be able to understand his unspoken fears and desires, and then help him in ways he never expected, like leading him to a hidden treasure that only they knew about because of their unique perception.
Maybe Hiccup, being a dragon rider, discovers that Mulan has a special connection to dragons in her own world. They could team up to protect the dragons from an evil force that is trying to hunt them down. Their relationship could develop as they face this common threat.
A great plot idea for a Dragons Dogma fanfic could be to create an alternate universe where the Dark Arisen is actually the good guy. The fanfic could explore the reasons behind this, like the real threat being something that the so - called 'good' side is hiding. Also, a story about a group of Pawns who break free from their Arisen and form their own community, dealing with the challenges of survival and self - discovery in the world of Dragons Dogma.
One idea could be a dragon from a hidden realm in the Bleach universe emerging and forging an alliance with Ichigo. The dragon could have unique powers that help Ichigo in his battles against the Hollows. For example, it might be able to breathe a special type of reiatsu - infused fire that can purify Hollows more effectively than a normal Soul Reaper's sword.
Well, you could focus on the environmental aspect. Maybe the dragons' fall was due to some imbalance in the magical environment they thrived in. A young mage discovers this and tries to save the dragons by restoring the balance. This would involve a lot of world - building, creating the magic system in detail, and showing how it affects the dragons and other creatures in the story.
One idea could be a dragon from a different realm arriving in the 'clash of dragons' world and having to learn the local customs and power dynamics among the dragons there. It could create new alliances and rivalries.
One idea could be that Hiccup, after turning into a dragon, has to learn to communicate with his old dragon friends in a new way. Since he now experiences the world as a dragon, he might discover new dragon abilities and secrets that were hidden from him before. Maybe he has to find a way to turn back, but in the process, he helps the dragon world solve a big problem, like dealing with a new and dangerous enemy.
In a fanfiction, Hiccup could be faced with a situation where the other gods are jealous of his status as the God of Dragons. They conspire to strip him of his powers. Hiccup then has to rely on his friends, both human and dragon, to regain his powers. He might go on a quest to find ancient artifacts that were used to first bestow the God of Dragons title upon him. This would involve a lot of adventure, battles, and self - discovery.
One idea could be that Hiccup discovers a new type of dragon with unique abilities. For example, a dragon that can change its color to blend in with its surroundings. This could lead to a whole new adventure as he tries to understand this dragon and protect it from those who might want to use it for bad purposes.
One idea could be that Hiccup discovers a new language that only the rarest of dragons understand, allowing him to communicate with a long - lost and extremely powerful dragon species. This could lead to him having to make difficult decisions about whether to share this knowledge with Berk or keep it a secret to protect the new dragons.
One interesting story could be about Hiccup's adventures in a new land with his dragons that he discovers by accident. Maybe he finds a hidden dragon lair with a rare breed of dragons.