It could be Harry. Since he is the main character in the original series, many fanfictions might still revolve around him. He has a complex relationship with both Draco and Severus, so it's easy to build a story with him as the central figure.
Draco could also be the protagonist. His character has a lot of room for development. He was a bully in the original series but had his own struggles. A fanfiction from his perspective, with his interactions with Harry and Severus, could be very interesting. He could be on a journey of redemption and self - discovery while dealing with the other two.
Although it's less common, Severus could be the protagonist. His past is full of mystery and pain. A fanfiction focused on him could explore his relationships with Harry and Draco in a different light. For example, a story could show how he tries to protect both of them from a threat that is related to his own past mistakes, while also trying to atone for his actions.
It's hard to say. Harry has a natural talent and courage, which could help him succeed. But Draco is well - versed in the pure - blood magic traditions and might have an edge in some aspects. Snape might be tougher on Harry due to their past, but that could also make Harry more determined. So it could really go either way depending on how the story is written.
Hermione would probably be one of the main characters to interact. She might be horrified at first to see Harry in such a situation and would try to find a way to free him. Ron could also be involved, perhaps being more impulsive in his attempts to rescue Harry, which might cause some problems. Dumbledore too would likely play a role. He might have some knowledge about the situation that he's not sharing right away, and his interactions with Severus would be crucial in determining Harry's fate.
Hermione would be a very likely ally. She's smart and resourceful, and could help Harry figure out the best ways to use magic against the Chitauri. Ron might also be there, with his loyalty and fighting skills. Additionally, some of the more experienced wizards or witches from Hogwarts could potentially join in to help Harry.
Voldemort would still be a very likely villain. He would see the Hulk as a threat or a tool to be used for his own evil purposes. He might try to control the Hulk's mind or use dark magic to make the Hulk do his bidding.
In some fanfictions, Draco and Severus might be portrayed as hurting Harry for various reasons. It could be due to the long - standing rivalry between Draco and Harry, with Draco's family's pure - blood ideology fueling his actions. Severus, on the other hand, has a complex relationship with Harry. His actions that seem to 'hurt' Harry could be misinterpreted. For example, his strictness in Potions class might be seen as a form of harm, but it could also be his way of trying to protect Harry in a convoluted way.
It could be Remus. He is the most level - headed of the group. He would be patient and understanding with a baby. His calm nature would be well - suited for taking care of baby Severus.
Obviously, Severus Snape and baby Harry Potter are the main characters. Severus would be in the role of the caregiver, which is a huge departure from his usual role in the original series.
At first, it might be very strained. Severus is used to seeing Draco as just another student or as Lucius's son. But once he realizes Draco is his own flesh and blood, he would start to show more concern. Draco, on the other hand, might be confused and a bit resentful at first. He has grown up with a certain image of Severus, and this new revelation shakes his world. Eventually, they would start to bond over shared interests, like potions and magic in general.
Well, it would change the story a great deal. Firstly, Harry would have a more stable home environment with Severus as his guardian. He wouldn't be so alone at the Dursleys'. Draco, on the other hand, might learn different values from Severus rather than just pure - blood supremacy from his family. And Hermione would have an adult figure in the wizarding world who truly understood her thirst for knowledge. The whole dynamic between the three of them would shift from rivalry to more of a sibling - like relationship under Severus' care.
I think magical creatures would also be customers. Maybe house - elves would be sent to pick up treats for their wizarding families. Hippogriffs might be lured by some special bird - shaped pastries. And even centaurs, if they were feeling a bit more adventurous, could come to the edge of the Forbidden Forest where the bakery might be located to get some goodies.