For the crossover, a good plot could be that a new type of ghost appears that is immune to Danny's ghostly powers. The Ghost Hunt team, which has encountered a similar situation before, offers their expertise. They introduce Danny to a special type of ectoplasm - based weapon that can harm this new ghost. Danny then teaches them some of his combat moves as a half - ghost to better fight the ghost.
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.
The scariest part might be when Danny faces really powerful and malevolent ghosts. Their appearance can be quite terrifying, with dark auras and menacing looks.
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.
There's also 'Phantom's Unlimited Potential'. This fanfiction delves into Danny's untapped powers. It shows how he discovers new ways to use his ghost powers, like being able to manipulate time on a small scale within the Ghost Zone. This gives him an edge over other powerful ghosts he encounters.
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.
One great fanfiction could be 'The Ascension of the Ghost King Danny'. In this, Danny might face new challenges as he fully embraces his role as the Ghost King. It could explore how he manages the Ghost Zone and his relationships with other ghosts in a more regal way.
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.