Family and friendship is also a big theme. In 'Supernatural', the Winchester brothers' bond is central, and in 'Btvs', Buffy has her group of friends, her 'Scooby Gang'. In crossover fanfiction, these relationships are often put to the test and developed further. The characters from both shows form new friendships or rivalries, which adds depth to the story. It can be really heartwarming or full of tension depending on how the author writes it.
Another theme is the idea of different cultures coming together. The characters from Sunnydale have a very different upbringing and set of values compared to those in the wizarding world. This can lead to some interesting character dynamics, like Hermione trying to understand Buffy's more street - smart ways or Xander being in awe of the magical grandeur of Hogwarts.
One common theme is the clash of different magical systems. Harry Potter has its own brand of magic with wands and spells, while Buffy has slayer powers and a different kind of magic related to demons and the supernatural. Fanfictions often explore how these two types of magic interact when the characters meet.
A third option could be 'Supernatural in Sunnydale'. This fanfiction is interesting as it shows how the Winchesters would handle the unique brand of evil in Sunnydale. It also delves into the relationships between the characters. For example, how Dean might interact with Spike, a complex vampire character from 'Btvs'. The story is well - written and has a good mix of humor and horror.
Another theme is the discovery of new powers and abilities. When the characters from the two universes meet, they might learn new things about their own powers or discover new abilities altogether. Like a Shadowhunter might learn some unique ways of banishing spirits from the Winchester brothers. This theme of self - discovery through interaction with a different world is quite prevalent.
One common theme is the clash of powers. Lucifer has his own set of demonic powers and in the Supernatural world, there are various powers like the Winchester brothers' hunting skills and the angels' powers. So, how these powers interact is often explored.
Another theme is the clash of worldviews. The Leverage crew is more about earthly justice and taking down corrupt humans, while the Supernatural guys are used to dealing with otherworldly threats. So in some fanfictions, there can be interesting discussions and conflicts arising from these different outlooks. For instance, Nate from Leverage might question the Winchesters' methods of just killing demons instead of trying to reform them or something.
Redemption is often explored. In Supernatural, many characters are on a journey of redemption, and when Lucifer is added to the mix, the idea of whether he can be redeemed or not becomes an interesting plot point. For example, some fanfictions show Lucifer being influenced by the Winchesters' sense of justice. Another common theme is the disruption of the natural order. Lucifer's presence in the Supernatural universe throws a wrench into the already complex balance of good and evil, heaven and hell, that exists in the series. This can lead to all sorts of chaos and interesting story developments.
Another common theme is the clash of different mythologies. The show Xander is from might have its own set of supernatural rules and creatures, and when combined with the Supernatural world, there are a lot of interesting interactions. This can lead to stories where the characters have to figure out how to deal with new and unexpected threats that come from the combination of these two different mythologies.
Power struggles are common. Both shows deal with powerful beings, so in the crossovers, there's often a fight for dominance between the characters from each universe.
A common theme is the clash of different power systems. Loki's Asgardian magic is very different from the magic and powers in the Supernatural world. So, stories often explore how these powers interact and sometimes conflict.