Hermione Granger could also be involved in an interesting way. Maybe she helps Harry understand the legalities and implications of the betrothal contract. She could also be a rival for Harry's affection, causing some tension in the story if she has feelings for him but he's betrothed to someone else.
Obviously, Harry Potter himself is the central character. His betrothed could be someone like Ginny Weasley in an alternate take on their relationship. Or it could be a completely new character created for the fanfiction, perhaps a powerful witch from a foreign wizarding school who has a betrothal contract with Harry as part of an international alliance.
Obviously, Harry Potter himself would be a main character. Since it's about a betrothal contract related to him. And probably the person he is betrothed to, whoever that may be in the fanfic's universe.
There might also be other characters who play important roles. For example, Daphne's family members. Her parents or sisters could be involved in the story, perhaps influencing her decisions regarding the betrothal. And of course, Harry's friends like Ron and Hermione could also be part of the story, either supporting or being skeptical about the betrothal.
The consequences of a betrothal contract for political gain in Harry Potter fanfiction are complex. Firstly, it could lead to a breakdown of relationships between different wizarding families that are not part of the contract. There may be envy or a sense of being left out. Secondly, for the young wizards or witches involved, it can be a very difficult situation. They may be forced to grow up quickly and take on political roles they are not ready for. And lastly, it can potentially lead to a new form of magical hierarchy, where families with successful betrothal contracts for political gain rise to the top, creating a more cut - throat and less inclusive wizarding society.
Luna Lovegood might also be a candidate. Her unique perspective and family background could bring a different dimension to the political aspect of the betrothal. Maybe her family has some hidden political influence that could be harnessed through the betrothal contract with Harry.
Well, in some fanfiction, Ginny Weasley might be the one in the betrothal contract with Harry, which could add more drama to their relationship. Or perhaps a character from another wizarding family, like a pure - blood from a foreign magical community. For example, a French witch from Beauxbatons. This would introduce new cultural elements into the story as they navigate the betrothal contract.
A third plotline might be about Harry trying to break the betrothal contract. He could feel that it's restricting his freedom and preventing him from being with the person he truly loves. This could lead to a whole adventure of finding loopholes in the wizarding laws regarding betrothals and facing the consequences of going against an old and powerful contract.
Obviously, Arianne herself is a central character. Her betrothed would be another important character. He could be a noble from another land, perhaps with a dark and mysterious past. Then there could be Arianne's family members, like her father who might be the one arranging the betrothal for political gain. Her friends or servants could also be characters, they might help her in her attempts to deal with the situation.
Harry Potter is at the heart of it. But don't forget about Pansy Parkinson. In some fanfictions, she can be rewritten to have a different side to her and be part of Harry's harem. Then there's also Daphne Greengrass. Her family's status in the wizarding world could play a role in a story about a marriage contract harem, and she could be one of the characters vying for Harry's attention.
A great plot in this type of fanfiction might involve the betrothal contract being a key to unlocking some long - forgotten magic. Harry and the other character involved in the contract (let's say it's a character from a different magical school) have to work together to figure out how to use this magic to defeat a new dark threat. They start off not getting along because of the forced betrothal, but as they learn more about the magic and each other, they develop a real bond.
Draco Malfoy is frequently in these fanfictions. His family's status in the wizarding world and his complex relationship with Harry and his friends make him an interesting addition to a story about a marriage contract potion. Ginny Weasley can also be a main character. Her relationship with Harry in the original series can be further explored or twisted in fanfiction involving the potion.