Well, Harry would be quite taken aback. He'd have to reevaluate his relationship with Hermione. He might worry that her loyalty has shifted. But at the same time, he would also see it as an opportunity to perhaps get some inside information on the Slytherins. Ron, on the other hand, would be extremely confused and probably not very happy about it. He might feel like Hermione is now part of the 'enemy' camp. However, as time goes on, they might come to accept it, especially if Hermione shows that her loyalties still lie with them. But it would definitely cause a lot of tension and confusion in their friendship at first.
Harry would be really shocked. He's used to seeing Hermione as his friend and fellow Gryffindor. If she was suddenly Draco's sister, he'd be very suspicious at first. He might think it was some kind of Slytherin plot. Ron would be even more flabbergasted. He has his own issues with Draco and to think that Hermione was related to him would be hard for Ron to accept. He might even be a bit jealous that Hermione now has this connection to a pure - blood family.
The Death Eaters would probably be divided. Some might see it as a great opportunity to gain more power through this union, while others might be suspicious of Hermione and worry that she will be a threat to their cause. The students at Hogwarts would be in an uproar. Hermione's friends would be ready to fight for her freedom. Ginny, for example, would be a strong advocate for Hermione. And Neville, who has grown so much in courage, would also stand up against this wrong - doing. There would be a lot of tension and drama within the wizarding community as a whole.
Harry would likely be very protective of Hermione. He's her best friend, after all. He might confront Draco immediately and try to get Hermione to see that she doesn't deserve this. Ron would probably be angry too, and might even be more impulsive in his reaction, perhaps getting into a fight with Draco.
Ron would be furious. His best friend being 'stolen' by his former rival would make him feel a mix of anger, betrayal, and jealousy. Harry would probably be in a difficult position. He's friends with both Ron and Hermione, so he might try to mediate at first, but if Draco is being difficult, he'd side with Ron. Ginny would be protective of her brother and would likely be very critical of Hermione for choosing Draco. The Slytherins, on the other hand, might be initially shocked but then accept it as Draco asserting his power and getting something he wants.
Harry would probably be furious. He's always been protective of Hermione, and he'd see Draco's actions as completely unacceptable. Ron might be a bit more vocal about it, perhaps even getting into a fight with Draco. Ginny, on the other hand, would likely comfort Hermione and be very supportive. Neville could be shocked and disappointed in Draco, as he's a character who values loyalty.
Harry would be completely shocked. He's known Hermione as his best friend and to see her with Lucius, who was once a Death Eater, would be almost unthinkable. He'd probably try to convince Hermione that she's made a huge mistake.
Their family life would be quite complex. There would be a clash between Hermione's values, which are more in line with equality and fairness, and the traditional pure - blood values of the Malfoy family. However, they might also find some common ground, like their love for magic. Draco's parents would likely have a hard time accepting Hermione at first, given her Muggle - born status (assuming that aspect remains the same). But over time, they might come to appreciate her intelligence and abilities.
The reactions would be diverse. In the Harry Potter universe, Ginny Weasley might be a bit jealous at first, seeing Hermione having such an amazing father figure. Neville Longbottom would probably look up to Hermione even more, seeing her as having an even greater heritage. In the Marvel world, Natasha Romanoff would be interested in how Hermione's upbringing in the wizarding world has shaped her, compared to Steve's upbringing in the military. Clint Barton might be a bit indifferent at first but would soon realize the significance of this connection. And the new generation of superheroes in the Marvel universe would see Hermione as a bridge between their world and the magical world, and would be eager to learn from her.
The other Hogwarts professors would be very concerned. McGonagall would likely be the first to take action. She would try to use the proper channels within the wizarding world to free Hermione. Snape, on the other hand, might have a more complex reaction. Depending on his own allegiances at the time in the fanfiction, he might be secretly helping or hindering the situation.
Draco's father, Lucius, might be very disdainful at first. He has a strong sense of pure - blood superiority and Hermione is a Muggle - born. His mother, Narcissa, might be more reserved in her dislike. She could be more focused on how Hermione's presence affects Draco.
The Slytherins would also have mixed reactions. Some might see it as a way to get one over on the Gryffindors, while others might be disgusted by Draco's actions, especially if they still hold traditional pure - blood views. The Hogwarts faculty would be in an uproar. Professors McGonagall would be deeply concerned about Hermione's future and the disruption to the school environment. And Snape might have some complicated feelings, given his past with Draco.