Obviously, Harry Potter himself is a main character as the story revolves around his new ability of time - mastery. Hermione Granger is also often involved. She would likely be the one to help Harry research about the time - related magic, using her vast knowledge of magic and books in the library.
In some fanfictions, characters from the past might also become main characters in a sense. For example, the founders of Hogwarts could be brought into the story if Harry's time - travels take him back to the founding days of the school. They could interact with Harry and help him understand the deeper magic behind his time - mastery ability.
Well, obviously Harry Potter himself is a main character as the title implies his role as the master of snakes. Hermione Granger is often involved too. She might be curious about Harry's new ability and help him research it, or she could be a bit wary at first given the negative connotations snakes have in the wizarding world.
In most 'time loop Harry Potter fanfiction', Harry is front and center. His character development within the loop is usually the focus. But Hermione is a key figure too. She could be the one to discover the magical theory behind the time loop. For example, she might find a long - forgotten spell or potion that could be related to time manipulation. Ron, although sometimes overshadowed by Harry and Hermione, can bring in the element of friendship and loyalty. In some cases, characters from the Death Eaters side like Bellatrix Lestrange might be involved if the time loop is related to a major battle or a plot against Voldemort. Their presence can add more danger and complexity to the story.
Ron Weasley could be another main character. He might be by Harry's side, providing the loyalty and friendship he always has. In some fanfictions, he could also gain some unique abilities or knowledge related to Harry's new state. And Dumbledore, even in death, might still have an influence. His past knowledge and wisdom could be a guiding force for Harry as he navigates his new immortality and power as the Master of Death.
Well, aside from the obvious ones like Harry and Hermione, Luna Lovegood can be a main character in some 'Harry Potter Master Legilimency' fanfictions. Her unique perspective on magic could lead to some interesting takes on Legilimency. Sirius Black is also a character that might be involved. He was a member of the Marauders and could have passed on some knowledge about Legilimency. And then there's Dumbledore. Given his vast knowledge and power, he could be guiding the main characters in their Legilimency studies or using it in his grand plans for the wizarding world.
Harry Potter himself is often involved. He might be the one to encounter the first signs of inflation, whether it's a magically inflating potion or an enchanted object. His friends, like Ron and Hermione, are also likely to be part of the story, helping him figure out what's going on.
Ron Weasley could also be a key figure. He might be Harry's loyal friend as always, standing by his side during all the changes that Harry is bringing about in the wizarding world as a god. And there could be new characters introduced as well, perhaps other gods or magical beings that interact with Harry in this new fanfiction realm.
In some cases, Albus Dumbledore could play an important role. His wisdom and power in the wizarding world would make him a key figure in any situation where the two different universes collide. He might be the one to first discover Alexstrasza's presence and figure out how to make use of her abilities in the fight against the dark forces in the Harry Potter world.
Obviously, Harry Potter himself is always a main character. He is the one most directly associated with the concept of death in the original series, what with his parents' death and his multiple near - death experiences.
Ron Weasley could be another main character. He might be initially skeptical about the piano's magic but then be amazed when he sees the extraordinary things it can do. Maybe he accidentally discovers a new function of the piano while fooling around with it in the Gryffindor common room.
Harry Potter himself could be one of the main characters in such fanfiction. Maybe he gets an automail limb after a particularly dangerous encounter with Voldemort. Hermione might also be involved, using her vast knowledge to help understand and improve the automail technology within the wizarding context.