One common theme is power struggle. Since Snape has his own power and influence in the wizarding world, and Harry is the 'Chosen One', a forced marriage between them could be a way for different factions to gain control. Another theme could be identity crisis. Harry would surely struggle with his identity as a Gryffindor hero being married to Snape, a former Death Eater and Slytherin.
Maybe it's a political move within the wizarding world. The Ministry of Magic might force this marriage to unite two powerful magical forces. Harry would then have to deal with his feelings for his friends like Hermione and Ron, who would be shocked. Snape, on the other hand, would have to adjust his view of Harry from a student to a partner. They could start to find common ground in their love for Hogwarts and magic in general.
Yes, there are some. You can start by looking on fanfiction platforms like Archive of Our Own. However, the idea of Harry being forced to marry Snape is quite an unusual and often dark or complex concept in fanfiction. Some stories might explore this in the context of a magically - bound contract or some sort of political intrigue within the wizarding world.
One common theme is the struggle for acceptance. The human character usually has to accept the fact that they are married to a dragon, which is a very different being. For example, in many stories, the human initially resists but then learns to see the dragon as more than just a fearsome creature.
Maybe some old pure - blood families who want to regain power. They view Harry as a symbol of the new order that they oppose, and Snape as a tool they can use. By forcing this marriage, they hope to control both of them and use their combined influence for their own dark purposes.
Well, a big theme is resistance. Hermione doesn't just accept the forced marriage easily. She fights against it in different ways, whether it's through magic or her wits. And there's the theme of unexpected love. Even though they start off in a bad situation, over time, they might develop feelings for each other. Also, there's the theme of social class conflict. Hermione being a Muggle - born and Draco a pure - blood, their union challenges the norms of the wizarding world, and this is often explored in these fanfictions.
In 'Markson Mark is forced to marry fanfiction', a common theme is the clash between personal will and external forces. Mark's own desires and plans are disrupted by the forced marriage. Another theme is adaptation. He has to adapt to the new situation of being married. There may also be themes of betrayal if there are elements where someone is behind the forced marriage for ulterior motives. And of course, the theme of redemption could also play a part if Mark or the other character tries to make up for the wrongs in the situation.
Perhaps there could be a magical object or spell involved that is causing this forced marriage. Harry and Snape might have to work together to find and break this spell. Along the way, they could learn more about each other's pasts and secrets, which could change their relationship from one of enmity to something more complex.
The other Hogwarts students would have a wide range of reactions. Some might be shocked and gossip about it. Neville, for example, might be sympathetic towards Harry. Draco Malfoy could use it as an opportunity to taunt Harry, but at the same time be a bit envious of the attention this situation brings. The teachers would also have different responses. McGonagall might be worried about the impact on Harry's education and future.
The theme of hidden motives also frequently appears. Snape's actions are often shrouded in mystery in the original story, and fanfictions expand on this. They explore what his real intentions are when he interacts with Harry, whether it's out of loyalty to Dumbledore, his own sense of justice, or something else entirely.
One common theme is redemption. For example, Draco often has a journey of redemption where he moves away from his family's dark past with the influence of Harry and Snape. Another theme is the exploration of complex relationships. They are characters who have had a lot of animosity in the original story, so in fanfiction, seeing how they navigate new relationships with each other is very interesting.