She becomes more nurturing. Usually, she's known for her strictness at Hogwarts, but when she adopts Harry, she softens up. For instance, she might show more patience when Harry makes mistakes in his magic studies.
One great 'Harry Potter Minerva McGonagall' fanfiction is 'The Transfiguration of McGonagall'. It delves into her early years as a teacher and how she dealt with the challenges. Another interesting one is 'McGonagall's Secret Mission' which shows her on a covert operation during the wizarding war. There's also 'Minerva's Heart' that focuses on her relationships with other Hogwarts staff members.
One common plotline is McGonagall protecting Harry from the Ministry of Magic when they wrongly suspect him of something. For instance, if the Ministry believes Harry is using Dark Magic, McGonagall stands up for him, using her influence and knowledge of Harry's character to prove his innocence.
Some characters in the harem might be developed as admirers of McGonagall's strict yet fair teaching style. They could be shown as constantly trying to impress her with their magical skills, like a young wizard who practices transfiguration just to get her attention.
One interesting fanfiction could be about Minerva McGonagall's early days as a teacher and how she interacted with a young Harry Potter. It might show her guiding him in secret before he even knew he was a wizard.
She often serves as a mentor. In many fanfics, she gives Harry extra guidance in his studies, especially in Transfiguration. This helps him become more proficient in magic faster.
There might be a fanfic that focuses on Minerva McGonagall's backstory in relation to Harry Potter. For example, it could explore her thoughts and feelings when she first saw Harry as a baby, knowing the prophecy. It could also show how she secretly protected him during his early years at Hogwarts, before he even knew about the danger he was in.
One great fanfiction could be 'A Bond Beyond Hogwarts'. It explores the unique relationship between Harry and Minerva in a post - war Hogwarts setting, with Harry seeking Minerva's guidance on becoming a better wizard and leader.
Another theme is wisdom. Since McGonagall is a very wise character, many fanfictions explore how she imparts her wisdom to others, especially Harry. They might have her giving advice on dealing with Voldemort or handling the pressures of being a young wizard in a dangerous time.
One common theme is her role as a mentor. In many fanfics, she is guiding students through difficult situations, much like she does in the original books.