Harry Potter himself could be the main character. He could be the one who stumbles into the world of Bioshock. His magical abilities would be put to the test against the threats in Rapture.
Hermione Granger and Bella Swan could also be main characters. Hermione could bring her intelligence and knowledge of magic, while Bella could provide insights into the Twilight world. They might start off as rivals, with Hermione thinking Bella is too naive and Bella finding Hermione too bossy, but then they grow to respect each other and work together.
Definitely Harry. He could form a special bond with a particular Pokegirl, maybe a fire - type Pokegirl, and they could go on adventures together in the wizarding world. Ron could also be a main character. He might be a bit more hesitant about the Pokegirls at first but then grow to like them. And there could be a new character, a Pokegirl trainer who comes to Hogwarts to introduce the concept of Pokegirls to the wizards, and she becomes an important part of the story.
Chef Ramsay would be the central figure. Then perhaps Hagrid could be a character. Hagrid is always dealing with magical creatures and he could provide some very interesting and unique ingredients for the kitchen. Also, Neville Longbottom could be there. He has a love for plants, and he could contribute by providing fresh magical herbs for cooking. And of course, the Hogwarts head chef, who would be resistant to change at first but gradually learn from Ramsay.
Well, it could be that a dark wizard in the Harry Potter universe discovers the ADAM and plasmids from Bioshock. He starts using them to create an army of super - powered Death Eaters. Harry and his allies have to figure out how to counter this new threat. They might travel to Rapture to find a way to neutralize the ADAM or find some kind of magical antidote. Harry could use his Patronus charm to fend off the more deranged splicers, and the Weasley twins could use their prank - making skills to mess with the Big Daddies.
Horus himself would be a central character. He would bring his own set of powers and a whole different mythology into the story. Dumbledore could also play a significant role. He's wise and powerful, and he might have some knowledge about Horus or the connection between the two worlds. Maybe he's been waiting for Horus to arrive for some greater purpose. And then there could be some minor characters like Neville Longbottom who could end up being unexpectedly helpful in the journey.
Obviously, Harry Potter and Merida would be the main characters. Harry with his knowledge of the wizarding world and his courage, and Merida with her strong - willed and adventurous spirit. They could team up to face challenges that require both magical and non - magical skills.
Obviously, Harry Potter could be one of the main characters. He could be the one to bridge the gap between the two worlds, using his courage and magic skills. Master Chief from Halo is also a great candidate. His combat experience and leadership would be valuable in the wizarding world full of new threats. Hermione would also be important as her intelligence could help in understanding the Halo technology.
Obviously, Harry Potter would be one of the main characters. He could be the one to bridge the gap between the wizarding world and the Transformers. Optimus Prime could also be a main character. His leadership and sense of justice would make him a great ally for Harry in the fight against evil. Hermione would also play an important role, using her intelligence to understand the Transformer technology and magic combination.
Obviously, Harry Potter himself could be a main character. He has the experience of dealing with dark forces, so he would be likely to take on the mystery of the FNAF animatronics. Hermione Granger would also be a key character as her knowledge of magic and books could help in understanding the situation. Maybe Freddy Fazbear could also be a sort of main character on the FNAF side, being the leader of the animatronics.
Obviously, Harry Potter himself would be one of the main characters. He could be the one to first encounter Spyro and start the whole adventure. Spyro would also be a main character, with his unique abilities and personality. Hermione could also play a big role as she would be very interested in learning about Spyro's world and how his magic works. And Ron, with his loyalty and sometimes comical nature, could provide some light - hearted moments during the more serious parts of the story.