Well, one possible plot could be that Danny Phantom is facing a powerful ghost that is beyond his normal capabilities to defeat. Wonder Woman, with her super strength, combat skills, and magic lasso, comes to his aid. She could use her lasso to restrain the ghost while Danny figures out a way to send it back to the Ghost Zone. They might also learn from each other. Danny could show Wonder Woman how to phase through objects in the human world in a different way than she does in her own realm, and Wonder Woman could teach Danny some hand - to - hand combat techniques that he lacks.
Danny Phantom can go intangible and invisible, which would be really useful for sneaking up on enemies. Wonder Woman has her super strength and speed. So, Danny could use his invisibility to get close to an enemy unnoticed, and then Wonder Woman could quickly rush in with her super strength to take the enemy down. For example, if they were facing a group of powerful demons, Danny could scout ahead invisibly and then signal Wonder Woman to attack.
One interesting crossover could be Danny using his ghost powers to assist Wonder Woman in a battle against a supernatural threat that her usual powers alone can't handle. For example, if there's a ghostly villain that can phase through her lasso and physical attacks, Danny's ability to turn intangible and fight other ghosts would come in handy.
The story might start with Danny being in a difficult situation in his own world. Wonder Woman, seeing his potential and the good in him, decides to adopt him. She could take him to Themyscira, her homeland. There, Danny would be exposed to a whole new culture and way of life. He might learn about their values, like truth and justice in a different context. And his powers could be enhanced or modified in some way by the magic and advanced knowledge on the island.
A possible plot could be that Youngblood gets into a feud with a powerful and ancient ghost. Danny Phantom steps in to help him because he realizes that Youngblood, despite his mischievous ways, doesn't deserve to be completely obliterated by this stronger foe. Danny uses his strategic thinking and a combination of his different ghost powers like invisibility and ecto - blasts to outwit the enemy.
Living with Wonder Woman could expose Danny to different sources of power. Themyscira might have some sort of energy or magic that could interact with his ghostly powers. This could lead to the development of new powers or a different form of his existing powers. For example, he could gain the ability to fly faster or have a more stealthy form of phasing that is not only useful for going through physical objects but also for sneaking around undetected in a more magical or energy - based sense. His powers would no longer be just about being a half - ghost, but a combination of his ghostly nature and the new elements he's exposed to through Wonder Woman and her world.
In a few fanfictions, Danny's ghostly enemies, such as Vlad Plasmius, might be paired in an adversarial way with Wonder Woman. This creates a conflict where Wonder Woman has to use her skills and powers to combat a foe that has different and unusual abilities compared to her usual adversaries.
The plot could change in terms of her love interests. Instead of the typical male - led romantic arcs, there could be new female - centered ones. For example, she might have a different type of relationship with a male character, where she takes the lead more often.
One plot idea could be that Danny Phantom is in Gotham City for some reason, maybe chasing a powerful ghost that has escaped into Batman's territory. He gets hurt during a fight with some of Gotham's villains who mistake him for a threat. Batman, being the detective he is, quickly figures out that Danny is not an ordinary 'meta' but a half - ghost. He helps Danny by providing him with a safe place to recover and using his resources to track down the ghost. Another idea is that Danny is hurt by a government agency that is trying to study his unique physiology. Batman steps in, using his influence to stop the agency from further harming Danny and helps him find a way to get back home to Amity Park.
In 'Danny Phantom as a Woman' fanfiction, a great aspect could be her fashion sense when it comes to her superhero/vigilante look. Instead of the traditional male - styled jumpsuit, she could have a more stylish and functional female - designed outfit. This could also tie into how she uses her femininity as a strength in combat and in dealing with other characters. Her interactions with female ghosts could also be a major part of the story, whether it's forming alliances or rivalries.