A great plot twist could be the appearance of unexpected allies or enemies. Maybe Lupin, who is also an outcast in some ways, shows up and has a different view on how Sirius should raise Harry. On the enemy side, Voldemort's followers might figure out that Sirius has Harry and target them both. Also, Sirius could find out that there are some special powers within Harry that are being suppressed by the wizarding world's norms, and he has to fight to let Harry develop those powers.
Well, it could be that Sirius, in his attempt to keep Harry safe, accidentally leads Harry into a world of dark magic that he didn't intend. For example, they might stumble upon an ancient and powerful dark artifact while on the run. Or perhaps Sirius discovers that Harry has a connection to a prophecy that is different from the one everyone thought, and this changes their entire journey. Maybe the wizarding world starts to believe that Sirius has turned Harry to the dark side because of their unorthodox upbringing, and they have to prove their innocence.
One possible plot could be that Sirius manages to escape with Harry undetected. He could then raise Harry in secret, perhaps in a wizarding community on the outskirts. Sirius would teach Harry all about his parents and the wizarding world, but also keep him hidden from Voldemort's remaining followers. Harry would grow up with a strong sense of family and justice, having Sirius as his sole parental figure.
One possible plot twist could be that the marriage law is part of a dark plot. Maybe a powerful dark wizard has enacted it to create chaos. Harry and Sirius, instead of simply accepting it, start to investigate. They discover that the law is linked to an ancient prophecy that could bring either great good or great evil depending on how they handle their forced marriage situation.
One possible plot could be that Sirius accidentally casts a spell that turns Harry into a baby. He then has to take care of Harry in this new form while trying to find a way to reverse the spell. He might face challenges like hiding Harry from the wrong people, and also dealing with Harry's baby - like needs such as feeding and changing diapers.
In the fanfiction, Tsunade might rescue baby Naruto from a dangerous experiment that was being carried out on him. As she rescues him, she realizes that Naruto has an extraordinary ability to resist the negative effects of the experiment. This leads her to believe that Naruto is destined for something great and she devotes herself to protecting him at all costs.
One possible plot twist could be that the kidnapper is actually related to Naruto in some way. Maybe a long - lost relative who has some sort of vendetta against the Hidden Leaf Village and thinks taking Naruto will give them leverage. Another could be that the kidnapper is being controlled by a greater evil force that wants to use Naruto's special powers for their own dark purposes. For example, they might want to extract the Nine - Tailed Fox's chakra from Naruto while he's still a baby and vulnerable.
A great plot twist could be that the pregnancy is not as straightforward as it seems. There could be some sort of magic or curse involved that changes the nature of the baby as it develops. For example, the baby could start to show signs of being a different species than expected. Also, what if there are other characters who want to claim the baby as their own for power or some other ulterior motive? This could lead to a lot of conflict and drama in the fanfiction.
One possible main plot twist could be that Sirius manages to completely hide Harry from the wizarding world's prying eyes until he comes of age. This would mean Harry grows up without the constant threat of Voldemort's followers finding him. Another twist could be that Sirius discovers some long - hidden magic within Harry that was dormant because of his upbringing with the Dursleys, but flourishes under Sirius's care.
One possible plot twist could be that Naruto is being taken back not for a warm welcome but as a suspect in some false accusations. Maybe there are hidden forces in Konoha that want to frame him to gain power.
One possible plot twist could be that Sirius Black, being a wanted man, has to constantly move with Harry to avoid capture. This would make Harry's childhood very different from the one at the Dursleys. He'd grow up learning about the wizarding world on the run, perhaps meeting some unique characters in hiding places.
One possible plot twist could be that Harry Dresden's magic system clashes with the wizarding world of Harry Potter. For example, Dresden's more rough - and - tumble approach to magic might get him in trouble with the Ministry of Magic. Another could be that Harry Potter, being raised by Dresden, develops a very different personality. He might be more street - smart and less naive compared to his original self. Also, there could be a plot twist where the enemies from Dresden's world start targeting Harry Potter because of his connection to Dresden.