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.
One possible plot could be that Gordon Ramsay visits the Hogwarts kitchens. The house - elves are used to their traditional ways of cooking and are resistant to change. Ramsay tries to introduce modern muggle cooking techniques to them. For example, he might show them how to make a proper steak instead of just serving up mystery meat stew all the time. There could be chaos as the house - elves initially reject his ideas, but eventually come around when they see the students enjoying the new food.
Another possible main character could be a new student at Hogwarts who has a special talent for cooking. This student could be from a family of muggles who owned a restaurant. They bring their non - magical cooking knowledge combined with magic to try and turn the kitchen nightmare around. They would interact with the well - known Harry Potter characters and together they would work on solving the kitchen issues.
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.
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.
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.
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.
A powerful dementor - like being that has been corrupted by Asgardian dark magic. This entity could be draining the life force of both wizards and Asgardians. It would be up to Thor and Harry Potter to find a way to stop it, as it poses a threat to both of their worlds.
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.