There could be a fanfic where Danny and Ember accidentally swap powers. This leads to a series of comical and also dangerous situations. Danny has to figure out how to control Ember's power of influencing people through music while Ember struggles with Danny's more combat - oriented powers. It could be a story full of self - discovery for both of them.
One interesting fanfic concept is that Danny and Ember are forced to work together to save the Ghost Zone from a powerful, ancient evil. They must combine their powers and knowledge. Danny's scientific knowledge about the Ghost Zone and his powers, along with Ember's knowledge of the more mysterious and musical aspects of the Ghost Zone, could lead to a great adventure and a deepening of their relationship.
One characteristic is the unique character designs. Danny might be given dragon - like features such as scales, horns, or a tail. The stories also tend to have a lot of adventure elements. Danny could be on a quest to find a lost dragon artifact or to save a group of dragons from an evil force. And there's usually a focus on the relationship between Danny and the dragons, whether it's a friendship or a more complex power - related connection.
In this fanfiction, it could be that Danny Phantom meets a Danny Phantom from a parallel fan - made story. At first, they don't trust each other. But as they learn more about each other's worlds, they realize that there are some common elements that are being threatened. It could be that a powerful ghost is trying to rewrite all the fanfic universes related to Danny Phantom. So, they must combine their strengths and knowledge to stop this from happening.
One way to incorporate archaeoastronomy in a Danny Phantom fanfic could be by having Danny explore an ancient site. Maybe there's an old temple where the alignment of the stars and certain structures has a connection to the Ghost Zone. He could discover that the ancients used their knowledge of the stars to keep the Ghost Zone at bay or to harness its power in some way.
I'm not sure if there is such a fanfic. There are a lot of fanfics out there, but this concept might be a bit unusual or even against the original tone of the 'Danny Phantom' series. It's possible that some fans might create such a story in the realm of fanfiction, but I haven't personally come across it.
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 a fanfic where Danny discovers a new power that has unexpected consequences. For example, he might gain the ability to time - travel and has to deal with the chaos it causes in the timeline. Another idea is a fanfic that focuses on Danny's relationships in the ghost zone. Maybe he forms an alliance with a powerful but misunderstood ghost. A third idea could be a story where Danny has to go undercover as a human in a place full of ghosts who don't know he's half - ghost.
Another unique part is the way these fanfics can blend horror and action elements. Danny's possession can be a really spooky concept, like in some stories where he loses control of his body. But at the same time, there are always action - packed scenes as he tries to regain control or fight against the possessing force. It creates a great balance that sets these fanfics apart from other types of fan works.
One idea could be that the Totally Spies are sent on a mission to investigate some strange paranormal activities. They then discover Danny Phantom's world and team up with him to stop an evil force that is using both magic and technology to take over the world. Danny could teach them about the Ghost Zone and they could share their spy skills with Danny.