In a sense, it could be thought of as related to the idea of Ghost Rider fanfiction. Danny Phantom is about a boy who becomes a half - ghost and has to navigate a world of ghosts and other strange phenomena. This is somewhat similar to Ghost Rider's journey with his otherworldly powers. But Danny Phantom is an independent creation with its own lore. It has its own backstory for Danny's transformation, his relationships with other characters like his friends and family, and different antagonists. So while there may be some fanfiction - like connections, it stands on its own as a unique story.
In fanfiction, if Danny Phantom becomes a full ghost, he might gain enhanced powers. He could have better control over intangibility and invisibility. Maybe he could travel through different dimensions more easily, like the Ghost Zone. Also, his appearance might change more towards a typical ghostly form, with more ethereal features.
One common theme is Danny's struggle with his dual identity as a human and a ghost. In full ghost Danny Phantom fanfictions, this struggle often takes on new dimensions. Another theme is the exploration of the ghost zone and its various inhabitants. It could be about Danny making new friends or enemies in the ghost zone.
One great Danny Phantom Ghost King fanfiction is 'The Reign of the Ghost King'. It delves deep into Danny's new role as the Ghost King, exploring how he balances his human life with his ghostly duties. The character development is really well - done in this fic.
One idea could be that Danny, as a half - ghost, has to prove himself to the Ghost King. Maybe there's a tournament in the Ghost Zone where Danny enters to show his worth. This could lead to some epic battles and alliances with other ghosts.
In a lot of fanfictions, Danny himself often becomes the most powerful ghost. As he grows and learns to control his powers better, he can surpass many of the traditional powerful ghosts in the show. For example, in some fics, he gains the ability to absorb other ghosts' powers, making him extremely formidable.
Archive of Our Own (AO3) is also a great place. There are many well - written 'Danny Phantom' fanfictions there. The tagging system makes it easy to find the ones about ghost speak. You might have to do a bit more digging compared to fanfiction.net, but it's worth it as the quality of the stories can be really high.
One great 'Danny Phantom Ghost Speak' fanfiction is 'The Ghostly Whispers'. It delves deep into Danny's ability to communicate with ghosts in a way that feels really true to the show. The author does an amazing job of creating new scenarios where Danny has to use his ghost speak to solve mysteries among the ghost world.
I really like 'Danny Meets the Rider'. In this fanfic, Danny accidentally crosses paths with Ghost Rider while dealing with a powerful ghost in his own town. The way the two characters interact, with Danny's quick thinking and Ghost Rider's brooding presence, makes for a really engaging read. It also has some cool fight scenes where their powers clash in unexpected ways.
Danny Phantom's ghost culture in fanfiction can be really exciting. Some fanfics focus on the traditions of ghosts, such as their ways of communication or how they mark their territories. This allows fans to add their own ideas to the existing concept of the show. It can also lead to some really cool crossovers with other fictional ghost concepts.