At first, Harry might be extremely confused. He trusts Sirius to a certain extent, but being kidnapped is still a shock. He would probably ask Sirius a lot of questions like 'Why are you doing this?' and 'Where are we going?'
On the other hand, Harry might also be a bit curious. Despite the situation, he knows Sirius well. He might wonder if there is a deeper reason behind this. So, while being cautious, he could also be listening to Sirius's explanations, trying to figure out what's really going on.
Harry may also feel a sense of adventure. Despite the situation, he's used to facing strange and dangerous things. He might start to think about how he can use this situation to his advantage, like finding out more about his parents or the secrets of the wizarding world that Sirius might know. He could be a bit excited as well as scared. For example, he might be thinking that this could be a chance to get away from the Dursleys for good.
Well, he might be in shock at first. I mean, Sirius is like a godfather to him, so the idea of marrying him is completely out of the ordinary. He could be filled with disbelief and confusion, not knowing how to even begin to process this strange turn of events.
Harry would probably be very defiant at first. He has faced Voldemort (Tom Riddle) before and he won't go down without a fight. He would likely try to use his magic skills to escape or at least hold Tom Riddle off until he can find a way out.
One possible plot twist could be that Sirius Black has a noble reason for 'kidnapping' Harry. Maybe he discovers a plot against Harry within Hogwarts that the school's authorities are ignoring. So, he takes Harry away to protect him. For example, he might find out that a certain teacher is under the influence of Voldemort and plans to harm Harry. Another twist could be that Sirius Black is being controlled by a dark magic spell and doesn't really mean to harm Harry. It could be a setup by Voldemort's followers to make Sirius look bad. Also, it could turn out that the 'kidnapping' is part of a secret training plan for Harry. Sirius wants to train Harry in some special magic skills away from the prying eyes of Hogwarts.
At first, Harry would likely be confused and scared. But this experience could force him to become more independent. He can't rely on Dumbledore or his friends at Hogwarts immediately. He has to learn to trust his own instincts and the bond he has with Sirius. This might make him more cautious in the future when it comes to trusting adults. For example, he might question Dumbledore's motives more often.
Well, Sirius is a very protective character. When he discovers that Harry is a Horcrux in the fanfic, he could initially be in denial. But once he accepts it, he'd likely start looking for ways to either protect Harry from Voldemort or find a way to remove the Horcrux part from Harry. He might also feel angry that Harry has been put in such a dangerous situation.
Sirius would probably be shocked at first. Then, he'd likely feel a deep sense of sadness and guilt. He might think that he should have been there more to protect Harry from getting those scars.
Sirius might be shocked. He'd probably feel a mix of horror and protectiveness. He'd be horrified that Voldemort has used Harry in such a way and would be even more determined to keep Harry safe from Voldemort's clutches.
At first, Harry would likely be shocked and angry. He's used to being in dangerous situations, but being kidnapped by Fleur, someone he thought was an ally, would be a big betrayal. He'd probably try to fight back immediately, using his magic if he could.
Harry could also try to reason with Voldemort. He might remind Voldemort of the prophecies and how killing him might not be in Voldemort's best interest. He could also try to appeal to any bit of humanity that might still be left in Voldemort, although that's a long shot.