Perhaps Danny, as Catwoman, starts off using his ghostly powers to steal valuable items in Gotham, but then realizes there are bigger threats and starts to use his powers for good, like helping Batman fight villains.
In 'danny phantom is catwoman by batman fanfiction', it might be that the writer is exploring a crossover in a unique way. Danny Phantom, who is from his own show, is being placed into the Batman world as Catwoman. This could involve taking Danny's personality traits and melding them with the alluring and sneaky nature of Catwoman. For example, Danny's sense of justice from his own series could be translated into Catwoman's actions in Gotham, while also maintaining some of the mystery and charm associated with Catwoman.
Once upon a time, Danny Phantom was zipping through the Ghost Zone when he accidentally slipped through a portal that led him to Gotham City. There he saw Catwoman on a rooftop, about to pull off a heist. Danny decided to have some fun and turned invisible. He started to play tricks on Catwoman by moving things around her. Catwoman, being the astute thief she was, sensed something was off. She whipped out her whip, lashing out at the unseen force. Danny then revealed himself, and Catwoman was both shocked and intrigued. They soon realized they were both sort of outcasts in their own worlds. Danny, a half - ghost, and Catwoman, a thief with a heart of gold. They decided to team up for one night, causing chaos for the bad guys in Gotham in their own unique ways.
Danny Phantom might adjust by using his powers in new ways. For example, he could use his invisibility to help Catwoman during her heists or surveillance. His ghostly powers could give them an edge in Gotham's dangerous underworld. He may also learn new skills from Catwoman, like combat techniques and stealth. Over time, he'd start to see Catwoman as a new family member and adapt to the different rules and lifestyle of living with her.
A great plot could be that there's a new villain in Gotham who has the ability to manipulate both the living and the dead. Danny Phantom senses this from the Ghost Zone and decides to investigate. In Gotham, he meets Catwoman, who has also noticed something strange. They initially distrust each other but soon realize they need to work together. They discover that the villain is trying to create a portal to the Ghost Zone to release all the ghosts into the human world. Danny and Catwoman have to race against time. Danny uses his ghost powers to fight the ghostly minions of the villain, while Catwoman uses her street - smarts and agility to navigate Gotham and find the source of the villain's power. In the end, they manage to stop the villain and close the portal, and in the process, they become friends.
His ghostly wail, a very powerful attack, could be used as a last - resort weapon against powerful foes in the Batman universe. However, it also might attract unwanted attention from other supernatural entities. Danny would have to learn to control it better in the more urban and populated Gotham. This would add an interesting dynamic to the crime - fighting in Gotham as they would have to deal with the potential consequences of using such a powerful ability.
There could be a connection in terms of the themes they both explore. Danny Phantom often deals with themes of identity and using one's powers for good, and Batman is all about Bruce Wayne's dual identity and his fight for justice. A fanfiction writer might see these similarities and decide to blend the two, perhaps having Danny learn something from Batman's sense of justice or vice versa.
She might be very surprised at first. After all, Batman is not one to show his emotions so openly. But then she would likely be overjoyed. She has deep feelings for Batman too, and this proposal would be a confirmation of their complex relationship.
In the fanfiction scenario, if Danny Phantom were adopted by Batman, it would be a really interesting mix of two different fictional universes. Danny, with his unique ghostly abilities like intangibility and flight, would bring a new dimension to Batman's crime - fighting in Gotham. Batman, on the other hand, could offer Danny a more stable family environment and a sense of discipline. Danny could also learn a great deal about strategy and stealth from Batman, which would be useful in his battles against ghosts. And perhaps together, they could face threats that neither could handle alone, like some sort of supernatural - crime hybrid villains.
Danny's powers could be a huge asset. His intangibility could help him and Batman get into places that are otherwise inaccessible. His flight would give them an edge in chasing villains across rooftops. Also, his ghostly energy blasts could be used as a new form of weapon against the bad guys in Gotham.
One key element is the clash of different universes. Danny Phantom comes from a world of ghosts and supernatural, while Catwoman is from the gritty Gotham city. So, how the two worlds collide and interact is important.