Another theme is the power of love. Harry's love for Sirius gives him the strength and courage to face the many obstacles in his way. It's a theme that's often explored in fanfiction as it was also a big part of the original books. In these stories, Harry's love overcomes things like the dark magic surrounding Azkaban or the threats from Voldemort's followers.
The theme of self - discovery is also present. Through the process of trying to save Sirius, Harry often discovers more about his own magical abilities and his place in the wizarding world. He might learn new spells or find out about his own hidden powers, which helps him not only in saving Sirius but also in his overall growth as a wizard.
One common theme is sacrifice. Sirius is often willing to put his own life on the line to save Harry. For example, in many fics, he battles powerful dark forces without hesitation to protect the baby.
One common theme is redemption. Sirius often feels guilty for not being there for Harry earlier, and by saving him from abuse, he is redeeming himself in a way. For example, in many stories, he reflects on how he could have prevented Harry from going to the Dursleys in the first place.
One common theme is family loyalty. Sirius is driven by his love for his brother and his sense of family duty to save Regulus. It shows that no matter how estranged they may seem, family bonds are strong.
Frequently, there's a theme of Hermione's strength in the face of abuse. Even before Sirius saves her, she might be shown as trying to resist or endure. And then after being saved, her growth and how she overcomes the trauma can be a big part of the story. The relationship between Sirius and Hermione can also explore themes of mentorship, where Sirius helps her heal and become stronger.
Another theme is family. Since Harry lacks a proper family, Sirius becomes like family to him. Fanfictions explore how they create a family - like bond in the absence of Harry's real family. It can be really emotional.
One common theme is the idea of second chances. With Harry deaged, Sirius gets a chance to be a better guardian or mentor, sort of like a redo of their relationship. For example, in many stories, Sirius is able to prevent some of the traumas Harry faced in the original story.
Well, often there's a strong theme of family and connection. Since Sirius is like a father figure to Harry in the original series, in mpreg fics it can explore a new level of that bond through the pregnancy aspect. Another theme could be protection, as both characters would be very protective of the new life.
One common theme is redemption. Sirius often has a chance to redeem himself in the eyes of the wizarding world through his relationship with Harry. For example, in many stories, he proves that he's not the dangerous criminal some thought he was.
In 'Harry is Sirius' daughter' fanfiction, a prevalent theme is the exploration of alternative family structures. Given that the original Harry Potter series had Harry orphaned and with a rather complex family situation, this new concept completely reimagines his family. Another theme is the impact on existing relationships. For instance, how would Harry's relationships with her friends at Hogwarts change? Would they treat her differently knowing she was Sirius' daughter? There's also the theme of power dynamics. Sirius was a powerful wizard, and if Harry was his daughter, how would that affect her own power growth and development? How would the wizarding community view her in light of this new family connection? And finally, the theme of secrets and revelations is often present, as Harry discovers this new aspect of her identity and has to deal with the consequences of that discovery.
Well, a lot of these fanfictions focus on the idea of a found family becoming a real family. Sirius was already like a father figure to Harry, but making him the biological father intensifies that. There's also the theme of changing destinies. Harry's path in the wizarding world could be completely different. He might be more rebellious or more confident because of having Sirius as his dad. And, of course, the theme of love and loyalty within this new family unit is always present.