Who could be the main antagonist in a 'Harry and Tracey marriage contract' fanfiction?

One possible plot could be that Harry and Tracey enter into a marriage contract for convenience. Maybe Harry needs to inherit something and being married to Tracey is a condition. They start off as strangers but gradually get to know each other through the requirements of the contract. They face challenges from their families who initially don't understand their motives.

The pure - blood family that arranged the marriage contract could be the main antagonist. They might have a lot to lose in terms of status, power, or wealth if the contract is broken. So, they would do everything in their power to force Harry to uphold it, even using dark magic or underhanded tactics.

Voldemort could be an antagonist. Even if Tom is a character in the marriage contract, Voldemort's ideology and his followers might oppose the union as it could potentially change the power dynamics in the wizarding world that they are trying to control.

A rogue ninja who wants to steal the power of the contract for his own evil purposes could be the main antagonist. He might be jealous of the connection between Sakura and Itachi and wants to break it to gain the abilities they could potentially unlock together.

Maybe it's an ancient evil that was sealed away long ago and the colossus contract is the key to its release. This evil force would be the main antagonist as it tries to break free and cause chaos in the ninja world. It could be something like a powerful demon that was once defeated by the first Hokage but is now on the verge of coming back because of the colossus contract. Naruto would have to stop it with the power of the colossus.

Well, it could be an old enemy of Harry's who doesn't want to see him happy in this new relationship. Maybe a dark wizard who wants to disrupt the peace that the marriage might bring. Another option is a jealous rival of Susan's. Someone who had feelings for her before and now is enraged that she's in a marriage contract with Harry.

The main characters are obviously Harry Potter and Cho Chang. Harry is the famous wizard who defeated Voldemort, and Cho is his classmate who he had a bit of a romantic history with in the original books.

Well, of course it's Harry and Hermione. Harry, who has a destiny to fulfill in the wizarding world and Hermione, who supports him throughout their adventures. In the context of the marriage contract fanfiction, they are at the center of the story, with their relationship being the main focus. Their personalities, which are well - established in the original series, play a huge role in how they interact with each other in this new situation of the marriage contract.

The main characters are Harry Potter and Draco Malfoy, of course. Harry is the famous 'Chosen One' who has fought against Voldemort. Draco is from a pure - blood wizarding family, and has often been in conflict with Harry at Hogwarts.

Well, obviously Harry Potter is one of the main characters. He is the famous wizard who defeated Voldemort and is now thrust into this unexpected situation of a marriage contract.