In some fanfics, the pokemon themselves can be main characters. For example, a pokemon that has been hypnotized and is struggling to break free from the control. It might have to rely on its own instincts and the help of its friends (both pokemon and human) to regain its normal state. This type of main character allows the story to explore the pokemon's perspective and emotions more deeply.
There could also be a mysterious pokemon trainer who has a special ability to hypnotize pokemon. This character might be a bit of an enigma, with motives that are not clear at first. They could be either a villain trying to use hypnosis for their own gain or a misunderstood character who is actually trying to help pokemon in a different way through hypnosis.
Often, the main characters are trainers. Since they are the ones most closely associated with Pokemon, they are likely to be the ones affected by the hypnotic events. For example, a young trainer might be hypnotized by a Pokemon's special ability.
Often, the main character is an exiled pokemon itself. It could be a Pikachu that was exiled for accidentally causing a power outage in a major pokemon city. Another common main character could be a trainer who is sympathetic to the exiled pokemon and decides to help them.
The main characters can vary widely. Besides the obvious Litwick and related Pokemon, there could be a young protagonist who has a special ability to communicate with Pokemon spirits. This character might be on a quest to understand the true nature of the Litwick Mansion. There may also be a group of thieves in some fanfictions who are after the rumored treasures hidden in the mansion, which are guarded by the Litwick and other Pokemon.
Obviously, Harry himself is a main character. Then there are often Hufflepuff students like Cedric Diggory. He's a significant character as he represents the best of Hufflepuff - being brave, kind, and fair. Newt Scamander could also be included in some fics as he was a Hufflepuff. His knowledge of magical creatures can add an interesting element to the fanfic.
One main character could be a half - blood who has some knowledge about changelings. They act as a sort of mentor to the changeling main character. There might also be a house - elf who befriends the changeling. The house - elf could offer a different perspective on the wizarding world and help the changeling in times of trouble. Additionally, a magical creature like a centaur might play a role, as they are known for their wisdom and might be able to give the changeling some important advice.
Obviously, Hilda is one of the main characters. Since she is the one being hypnotized, the story likely revolves around her experiences and how she copes with the situation.
Often, Harry Potter himself can be a main character in such fanfics. Imagine him with the ability to shapeshift, which could give a new twist to his battles against Voldemort. He could transform into a snake to spy on the Death Eaters, for instance.
In these fanfics, Harry Potter is typically a central figure. He could be on a quest that takes him to the Spartan realm. Ron Weasley might tag along too, providing some comical relief while also being involved in the adventures. From the Spartan side, a strong and noble Spartan leader or hero would be present. This character would be intrigued by the magic that Harry and his friends bring and would want to learn more about it. They would all interact in various ways, facing challenges together.
Some of the more intelligent and powerful Pokemon themselves can be main characters in such fanfics. Pokemon like Mewtwo, which has great psychic abilities and a complex backstory, could be involved in mind - control situations, either as the one being controlled or the one doing the controlling.
Dumbledore might also be a significant character in some of these fanfics. Even though he is not a Potter, he has a strong connection to the family. He could be involved in setting up or enhancing the protections of the Potter house. And then there are the family's house - elves, who play a role in maintaining the house and its protection, and can sometimes be important characters in their own right.