Obviously, Harry Potter himself is a main character. Since he is becoming Lord Potter, he is at the center of the story. Hermione and Ron are likely to be important characters as well, as they are Harry's closest friends and will surely be involved in his new journey as Lord Potter.
One possible plotline could be Harry's new responsibilities as Lord Potter. He might have to deal with the politics within the wizarding world in a different way. Maybe he uses his new title to bring about changes in Hogwarts' curriculum or to improve the living conditions of some underprivileged wizarding families.
His old friends, especially Hermione and Ron. They have always been on the side of good and would not stand for Harry becoming a dark lord. They would try to stop him and bring him back to the light, so they would be the main antagonists from Harry's new perspective.
Well, one possible plot development could be that Harry starts to question the existing power structures in the wizarding world. Maybe he feels that the so - called good side has its own flaws and secrets. He might then begin to amass his own power, secretly at first, perhaps by seeking out dark magic spells that have been long forgotten. He could start to gather followers who are also disillusioned with the status quo.
In 'harry becomes lord potter at 7 fanfiction', Harry is the main character, but there could be other important characters too. Maybe there are some members of the Potter family's old allies who come forward to help Harry. For example, the Longbottoms could be important as they have a long - standing relationship with the Potters. And then there might be some antagonists, like the Malfoys, who could be envious or try to undermine Harry because of his new title.
In fanfiction, if Harry Potter becomes Lord, he might gain a great deal of power and influence. He could use this new status to reform the wizarding world. For example, he could change the way Hogwarts is run, introduce new magical studies, or even restructure the Ministry of Magic to be more just and efficient.
Ron is also there. He could be Harry's right - hand man in some adventures related to his lordship. For example, when Harry has to deal with some dark wizards threatening his lands, Ron might be by his side, using his Weasley - family - taught magic skills.
Well, if Harry Potter becomes a Jedi, he'd be an extremely powerful force user. He already has his wizarding skills like magic spells, and adding Jedi abilities like using the Force for telekinesis, mind tricks, and lightsaber combat would make him nearly unbeatable. His wand could potentially be used in a unique way in combination with a lightsaber. Maybe he could channel magic through the lightsaber for even more powerful attacks. He might also use his Jedi training to be more in tune with his emotions, which could be both a strength and a weakness, just like in the Star Wars universe.