One common theme is his growth as a sorcerer. Many fanfics focus on how he hones his skills and becomes stronger. Another theme is his relationships, like his friendship with Yuji or his complex connection with the Zenin family.
There's a fanfic called 'Megumi Fushiguro: A Different Path'. In this, the author takes Megumi on a completely different adventure from the original story line. It's really interesting to see how his character develops in this new scenario. Also, 'Megumi's Hidden Powers' is a fanfic that uncovers some potential powers that Megumi could have, which makes for an exciting read.
Maybe there are friends of the dad or some antagonists who oppose the dad's heroic actions. There might also be neighbors or colleagues who play important roles in the story.
The two main characters are 'rich dad' and 'poor dad'. Rich dad is the father of the author's friend and represents the mindset of the wealthy. Poor dad is the author's own father, who has a more traditional and less financially savvy approach to life and money.
The dad in the Christmas story is Joseph. He was an important part of the events leading up to and following Jesus' birth. Joseph was from the line of David, which was also prophesied in the Bible. His obedience to God's will, like taking Mary as his wife and traveling to Bethlehem, was essential in the overall Christmas narrative.
In 'Pulp Fiction', there isn't a character simply named 'dad' in a very straightforward sense. However, if we consider the idea of father - like figures, Marsellus Wallace could be seen as a sort of authority or 'father' figure in the criminal underworld depicted in the movie. He has power and influence, and the other characters often have to answer to him, much like how people would to a father figure in a hierarchical setting.