There could be a plot point about Harry's relationship with the Black family's house - elf or other magical creatures associated with the family. He might have to deal with their loyalty issues. And perhaps there are other external forces that try to use Harry's control over the Black family for their own purposes. This could lead to a series of conflicts and challenges for Harry as he tries to keep the Black family under his control while also protecting them from outside threats.
Well, it could be through some sort of magical inheritance. Maybe he discovers a long - lost spell or charm that gives him power over the Black family's affairs. It might also be related to his connection with Sirius Black. Since Sirius was part of the Black family and Harry was so close to him, there could be some kind of transfer of influence.
One possible plot could be that Harry discovers some ancient magic that gives him the power to control the Black family Grim. He might use this power to uncover secrets within the Black family that were long hidden. Maybe he uses it to protect the family from dark forces that are after their power or knowledge related to the Grim.
There's also the possibility that an ancient dark magic entity, which has some connection to the Grim, is the main antagonist. It tries to manipulate Harry into using the Grim's power in a way that will free it from its ancient prison or some such situation, and Harry has to resist this while still maintaining control over the Grim.
In some 'naruto controls water fanfic', the plot might revolve around Naruto using his water powers to save his friends or the village. For example, when the village is under attack by a fire - based enemy, his water powers become crucial. Also, there could be a plot about him competing in a ninja tournament where his water - based jutsus give him an edge and he has to face opponents with different elemental powers.
One interesting plot point could be the restoration of the Black family's honor. Maybe a long - lost heir emerges to bring the family back to its former glory in the wizarding world. Another could be the exploration of the family's dark magic secrets and how they are dealt with in the context of the fanfic.
One plot point could be the initial encounter. Harry might be on a mission related to Voldemort and come across Bellatrix. At first, they would be hostile towards each other, but then Harry sees something in her that makes him curious. Another point would be the development of trust. As they interact more, Bellatrix starts to open up about her past, like her family's influence on her path to the dark side.
Well, in a 'harry controls hermione fanfic', it might be that the author is exploring a different dynamic between the two characters. It could be a plot device to create new and interesting scenarios. For example, perhaps Harry has been given a magical object that gives him the ability to control Hermione's movements for a short time, and this leads to various adventures and challenges as they try to deal with this strange situation. It could also be a more psychological form of control, like Harry having some knowledge that he uses to manipulate Hermione's behavior in a way that moves the story forward.
In the Grimm's version of the little mermaid story, the mermaid falls in love with a human prince. She makes a deal with a sea witch to get legs in exchange for her voice. She endures great pain while on land. However, things don't go as smoothly as she hoped in her relationship with the prince. Eventually, she faces a tragic end, different from the more well - known Disney version.
In Pokemon Black, the main plot point is dealing with Team Plasma's ideology of Pokemon liberation. The protagonist aims to become a strong trainer while countering Team Plasma's actions. In Black 2, a major plot point is the resurgence of Team Plasma in a different form. Another is exploring the new areas and features in Unova two years after the first game.
In many of these fanfics, the plot includes Harry using his dragon form to his advantage. For example, he could have enhanced senses and strength in that form. This might lead to him uncovering secrets in the wizarding world that were previously hidden. Also, his relationships change. His friends might be initially shocked but then support him. And there could be enemies who try to use his dragon form against him, creating a lot of conflict and drama in the story.