Well, perhaps Draco has some new-found knowledge or a secret weapon that gives him confidence to take on Harry for the Lord Black title. Harry, on the other hand, may be initially reluctant to engage in the duel but is pushed into it to protect the legacy of the Black family. During the duel, they both could discover things about the Black family history that changes their perspective on the whole matter.
In this fanfiction scenario, the duel between Draco and Harry for the Lord Black title could be a very complex affair. Draco might be influenced by his family's past association with the Black family and his own desire to prove himself better than Harry. Harry, being the hero type, would be more concerned about the well - being of the wizarding world and the implications of Draco becoming Lord Black. There could be magical artifacts involved that are tied to the Black family that both try to use during the duel. The duel could also attract the attention of other characters like Hermione and Ron, who might try to interfere or help Harry in some way.
In this fanfiction, Draco would flaunt his family's signature spells. His magic would be more calculated and strategic, like setting up magical traps before the duel even starts. Harry's magical abilities would be more about his connection to his friends and the positive energy that gives him. He could use magic that is enhanced by his loyalty and friendship, like a spell that gets stronger the more he thinks about protecting those he cares about. During the duel, both of them would have to constantly adapt their magical abilities to counter each other's moves.
One possible plotline could be that Harry discovers he has a hidden connection to the Black family that makes him Lord Black. This could lead to him having new powers or responsibilities within the wizarding world, and he might have to deal with the complex politics and family secrets of the Blacks.
One possible plotline could be that they discover they are brothers early on in their Hogwarts years. This would cause a huge stir among the students and teachers. They might initially struggle to accept it, especially given their past animosity. But as they get to know each other better, they start to form a bond and protect each other from the various threats in the wizarding world.
In some fanfictions, it could be a case of a powerful curse that forces Harry to act against his will. The curse might be placed on him by a powerful dark wizard who wants to create chaos in the wizarding world. Draco is just an unfortunate victim of this curse as Harry, unable to control himself, kills Draco. This then sets off a chain of events where Harry has to deal with the guilt and the consequences of his actions.
One possible plotline could be that Harry, through some magical accident or inheritance, comes to own Draco's family manor. Draco is then forced to interact with Harry on Harry's terms to regain his family's pride. Another could be that Harry wins a bet against Draco and the terms of the bet are such that Harry now has ownership over Draco's time, making Draco do tasks for Harry.
A plot could involve Harry dealing with the Black family's old grudges and feuds. As Lord Black, he has to sort out the mess left behind by generations of Blacks. He might have to mediate between different branches of the family who have been at odds for centuries. Harry could use his own experiences of friendship and loyalty from his time at Hogwarts to try and heal the rifts within the Black family. This would not only change the Black family but also have a positive impact on the overall wizarding society as the Black family has a significant influence.
In this fanfiction, a plotline could involve Harry being magically bound to Draco's mom in some way. As a result, he has to stay close to Draco to protect the bond. This could lead to many comical and tense situations between Harry and Draco as they navigate their new relationship. Another possibility is that Draco's mom has left behind a powerful artifact, and Harry is the only one who can find it. Draco, thinking Harry has ulterior motives, tries to stop him at first but then realizes they need to work together. Also, there could be a plotline where Harry accidentally uses a spell that links his mind to Draco's mom, and he has to figure out how to break the link while dealing with Draco's reactions.
One plotline could center around them adopting a child. Given their complex backgrounds, they would face unique challenges in raising a child. They might have to deal with the child being bullied because of their fathers' history. The fanfiction could show how they support each other and the child through these difficult times. Also, they could go on adventures together as a family, exploring parts of the wizarding world that are not well - known. It could be a way for them to bond and create new memories away from the prying eyes of the wizarding society.
One possible plotline could be that in a dangerous magical situation, like a dark wizard attack during a Hogwarts event. Draco, despite his previous animosity towards Harry, has a change of heart. Maybe he overhears some information about the attack being part of a larger plot against Harry specifically. So, Draco steps in and uses his family's knowledge of certain spells or magic artifacts to save Harry. Another could be in a potion - making class gone wrong where Harry is about to be seriously injured by a rogue potion effect, and Draco, who is actually quite good at potions, quickly whips up an antidote or counter - spell to save Harry.
One possible plotline could be that Harry betrays Draco in a duel. Maybe there was some sort of misunderstanding or a secret deal that Harry made with someone else that required him to turn on Draco during the duel. For example, if there was a dark wizard threatening Harry's friends and the only way to save them was to sacrifice Draco in the duel by using a forbidden spell against him.