Well, it could be that Danny has been separated from his body for a long time in the fanfiction. When he finally locates it, his body might be in a weakened state. He might need to use his ghost powers in creative ways to revive and reunite with his body. There could also be some emotional moments as he reflects on how much he's missed being in his own physical form.
One possible antagonist could be Vlad Masters. He might want to keep Danny's body for his own evil purposes, like using it to gain more power or to take over Danny's life. Another could be a powerful and vengeful ghost who has a grudge against Danny and sees his body as a way to get back at him.
Perhaps Danny's friends find out that he has been caught by his parents. They could come to his rescue. Tucker might use his tech - savvy skills to hack into the Fenton's security systems, and Sam could try to reason with Danny's parents. Together, they could try to convince Danny's parents that Danny is still the same person they love, just with some extraordinary powers.
He could be in a situation where he's trapped in the Ghost Zone. His friends might have to figure out a way to get to him. They could use some of Tucker's new inventions, like a Ghost Zone - traversing vehicle. They'd face many challenges along the way, such as avoiding other dangerous ghosts.
She could face a lot of challenges. For example, she might be shunned by some in the ghost world because of her half - human heritage from Danny. Or she could struggle to fit in with humans because of her ghostly powers. It would be a complex situation for her to navigate.
Danny might use his powers to cheat in gym class without getting caught. For instance, he could use his super strength to win a weight - lifting competition or his flight to win a race. But he has to be careful not to arouse suspicion among his classmates.
In 'Danny Phantom Goes to School' fanfiction, there could be a new character who is also a half - ghost and they become friends or rivals with Danny. They could team up to fight a powerful ghost that has infiltrated the school's science lab. The school setting also allows for some interesting interactions between Danny's human friends and his ghost - hunting side. For example, his friends might accidentally discover his secret identity while they are all involved in a school project.
Well, in the 'Danny Phantom becomes colder' fanfiction, it could be that Danny's connection to the Ghost Zone is somehow altered. This alteration makes him colder in nature. His ectoplasmic energy could be affected, causing his body to emit a cold aura. His relationships might also suffer. Sam and Tucker may initially be confused by his sudden change in behavior. They might think he's pushing them away on purpose. Danny, on the other hand, could be struggling with this new coldness inside him, not fully understanding what's happening. He might try to isolate himself to protect others from this strange new aspect of himself, which would add a layer of emotional drama to the story.
Perhaps the Avengers are initially skeptical of Danny's abilities, thinking he's just some kid. But then Danny shows them what he can do, like his ghostly wail which could be a powerful weapon against their foes. They might then start to respect him and work together as a team. Danny could also learn a thing or two from the Avengers about teamwork and strategy.
In a Danny Phantom fanfiction involving Valerie and Nathan, they could become allies in the fight against ghosts. Maybe Nathan discovers Valerie's secret identity and offers his technological expertise to help her upgrade her ghost - hunting gear. This would make them a formidable team, taking on powerful ghosts that Danny might have trouble with on his own.
In a fanfiction, if Danny overshadows Sam, he might be trying to protect her from a danger she's unaware of. Maybe there's a ghost that's targeting Sam, and Danny can't be with her all the time, so he overshadows her to give her the ability to defend herself. He could transfer some of his ghost powers to her for a short time. This would create a lot of drama and action in the story, with Sam having to figure out these new powers while still being herself at the core.