One big challenge could be public opinion. The wizarding community has a long - held grudge against Death Eaters. So Harry would face a lot of criticism and distrust from the public. People might think he's gone to the dark side or that he's being naive.
There could be threats from the remaining Death Eater factions. They might see Harry's marriage as a way to get to him or they might think the Death Eater he married is a traitor. This could put both Harry and his new partner in danger. Also, if they have kids, the kids might face discrimination because of their mother's past as a Death Eater.
One challenge could be cultural differences. Harry is from a world where magic is more about spells and potions, while Zatanna's magic is more about incantations and showmanship. Another challenge might be the acceptance of their relationship by their respective communities. Some in the wizarding world might think Zatanna's magic is too different and unorthodox, and some in Zatanna's world might not understand the ways of the wizarding world. Also, they might face villains who target them because of their combined power and the threat they pose to the status quo.
One possible theme could be the exploration of life and death. Since Harry is marrying Death, it might delve into the deeper meaning of mortality and how it relates to the magical world. Another theme could be power. Death in the Harry Potter universe has a certain power, and this could be explored in the relationship with Harry.
The cultural differences between the wizarding world and the DC universe would also be a problem. They have different ways of doing things, different social norms. Harry is used to a world where magic is the norm, and a DC villain might not understand or respect that. And vice versa, the villain's world of high - tech and superheroes might be very foreign to Harry.
Well, one popular 'harry marries a death eater' fanfic might be 'Dark Alliances'. In it, the author creates a complex scenario where Harry's relationship with the Death Eater unfolds in a world full of political intrigue and hidden motives. It's really interesting as it shows how Harry has to navigate his new relationship while also dealing with the wizarding world's perception of him being with someone from the 'dark side'.
One challenge could be dealing with the change in how others perceive him. People who knew him as a boy might have a hard time adjusting, and he could face prejudice or misunderstandings. Another challenge might be adapting to the physical differences. For example, if there are differences in strength or body shape, it could affect his ability to do certain things like play Quidditch as he used to.
One possible storyline could be that the Death Eater has a change of heart due to a past connection with Harry's parents. Maybe they were once friends before turning to the dark side, and seeing Harry in danger awakens their conscience. For example, they might remember a kindness Harry's mother showed them long ago. Another idea is that the Death Eater is acting out of self - interest. They realize that Harry's death could lead to chaos that might not be in their favor. So, they save Harry to maintain some sort of order in the wizarding world that benefits them. A third possibility is that the Death Eater has a secret prophecy or prediction that saving Harry will lead to their own redemption or a great reward in the future.
Well, perhaps Harry discovers some secrets about his family that make him think the Death Eaters' ideology isn't all bad. He could start to secretly interact with some of the less extreme Death Eaters, learning their ways and starting to form a strange sort of admiration for them. But this would be a very different take from the original story where Harry is firmly on the side of good.
One big challenge could be Snape's natural inclination towards the Dark Arts. Harry would have to constantly keep an eye on Snape and try to steer him away from that path. Also, Snape's personality is often prickly and guarded. Harry would need to break through those barriers to really connect with him. Another challenge might be the expectations of the wizarding community. People might not understand why Harry is raising Snape and could be suspicious or judgmental.
One challenge could be finding a safe place to stay. The wizarding world is not that big, and there are many places that are easily detectable. They would need to use magic carefully to avoid leaving a trail for those who might be looking for them.
He might face challenges in terms of curriculum development. There would be pressure to update the courses to keep up with the changing times in the wizarding world. Additionally, he would need to handle the security threats that still lurk, such as the remaining Death Eaters or new dark forces. He has to protect the students and the school's secrets while also allowing for a free and open learning environment.