Obviously, Cinderella and the prince would be likely to be featured. They are the central characters of the original story, and any continuation would probably revolve around them and their relationship.
The step - sisters could also be important characters. Their relationship with Cinderella could be explored further. Maybe they have changed for the better or are still causing trouble in the new fanfiction.
Naruto is a very likely character. Given his rebellious nature and his history of being an outcast in some ways, it's easy to imagine a scenario where he gets caught up in something that lands him in prison. His determination to break free and his loyalty to his friends would make for an interesting story.
Well, for sure Yugi would be in it. He has that special bond with the spirit of the Millennium Puzzle, and that could lead to all sorts of adventures in the world of The Ocarina of Time. Then there's Joey. His loyalty to Yugi and his own dueling skills could play a role. In terms of The Ocarina of Time characters, Zelda would likely be involved. She has her own powers and knowledge, and her interaction with the Yu - Gi - Oh! characters, especially Yugi, could be really interesting. And of course, Ganon could be a major antagonist in the fanfiction, causing trouble for both sets of characters.
For the Infamous side, Cole MacGrath would be a likely candidate. His powerful electrical abilities would make for an interesting dynamic in the Overwatch universe. On the Overwatch side, Tracer would be a great fit. Her speed and agility could contrast with Cole's more brute - force power. Also, Reinhardt could be involved. His chivalrous and protective nature would be interesting to see interacting with the Infamous characters.
Shepard from Mass Effect is a very likely character. Given their leadership skills and experience in dealing with various alien threats, they would be a natural fit in a crossover. They could potentially lead XCOM forces or at least be a key figure in coordinating between the two universes.
For Naruto side, Naruto himself is very likely. His determination and growth arc can be interestingly combined with DC elements. Also, Sasuke with his powerful Sharingan could have some cool interactions in the DC universe.
Iruka Sensei could also be a prominent character. He was an important figure in Naruto's early life. In a second - chance story, he might play a role in guiding Naruto in new ways, or perhaps Naruto could use his second chance to repay Iruka's kindness in a more significant manner.
Sasuke would be a likely character. He already has a dark past and a tendency towards brooding and seeking power, which would fit well in a 'world of darkness' setting. Orochimaru is another one. His experiments and his general amorality make him a natural for a darker Naruto story. And of course, Madara Uchiha. His grand and often cruel plans for the ninja world would be further explored in a darker fanfiction.
Takato from Digimon Tamers and Tai from Digimon Digidestined are very likely to be featured. Takato is the main character in Tamers, and Tai is a well - known and important figure among the Digidestined. Their leadership qualities could bring an interesting dynamic when they meet. Also, Guilmon from Tamers and Agumon from Digidestined might be there, as they are the iconic Digimon partners of Takato and Tai respectively.
Well, for sure Harry Potter is a top pick. His connection to Gringotts started early on when he first visited to get his inheritance. Hermione would be there as she's the brains of the group and would be curious about any magical lore associated with Gringotts. Ron, with his family's financial struggles, could also play an important role. The goblin bankers are a given as they are the heart of Gringotts. In terms of crossover characters, if it was a crossover with 'Alice in Wonderland', the Cheshire Cat could make an appearance. It could be lured by the shiny objects in Gringotts and cause some chaos as it tries to steal something, with Harry and his friends having to stop it.
Obviously, Harry Potter himself would be a central character. Ron and Hermione, his closest friends, would also likely be in it. Ginny, as Harry's love interest, would probably play a significant role too. Other characters like Neville, who has grown into a strong wizard, could also be featured. And of course, we might see some of the old Hogwarts professors, perhaps McGonagall still guiding the school in some way.