One common plotline could be that Spike kidnaps Xander for some sort of revenge against Buffy. Maybe he thinks by taking Xander, he can draw Buffy out and have a final showdown with her. Another could be that Spike is under a spell or some dark influence that makes him kidnap Xander, and throughout the fanfiction, Xander tries to break that influence over Spike.
A plotline could involve Spike kidnapping Xander in a fit of jealousy. Maybe he sees Xander getting too close to a certain female character that Spike has an interest in. This then forces Xander to deal with Spike's unpredictable emotions while also trying to find a way to free himself. The story might also explore how the other characters react to Xander's disappearance and suspect Spike right away or be completely oblivious.
Buffy would probably be involved. Since she's the slayer and Xander is her friend, she'd be on a mission to rescue him from Spike. Willow could also be in it. As Xander's best friend and a powerful witch, she'd use her magic to try and find Xander or fight against Spike. And Giles, too. He'd be the one providing knowledge and guidance on how to deal with a vampire like Spike who has kidnapped Xander.
One common theme is the exploration of their unlikely connection. Since they are so different in the original context, fanfiction often focuses on how they bridge that gap.
Since I don't have specific knowledge about 'boypussy xander spike' fanfic, I can only guess. It might have themes related to the relationship between the two characters. Maybe themes of loyalty, or how they face challenges together. It could also potentially have themes of growth, as the characters develop throughout the story.
Perhaps Xander is kidnapped by Spike because Spike has been cursed or influenced by some dark magic. In this case, he may not be fully in control of his actions. And as the story progresses, Xander could try to find a way to break the spell on Spike while also trying to escape. Another plot could be that a third party hires Spike to kidnap Xander, and Spike reluctantly agrees for some personal gain, like money or a way to get rid of his own enemies. Then Xander and Spike might end up having to work together to face the real threat behind the kidnapping.
Yes, there might be. You can start by looking on popular fanfiction platforms like Archive of Our Own or FanFiction.net. Just search for 'Xander Spike kidnapped' in their search bars and see what comes up.
One common plotline is Spike feeling jealous and angry. For example, if Twilight starts spending more time with a new pony friend, Spike might feel left out and his jealousy could turn into anger. He could then go on a little adventure to prove his importance to Twilight.
One great Spike Xander slash fanfiction is 'The Unlikely Bond'. It beautifully explores their relationship in a post - apocalyptic setting. The author does an amazing job of delving into their complex emotions.
One possible plotline could be Spike and Fluttershy going on adventures together in the forest. They might discover new magical creatures and in the process, their bond deepens. Another could be them facing a misunderstanding in Ponyville that makes them realize how much they truly care for each other.
Betrayal can also be a theme. He could be hurt by someone he trusted, like a friend or a love interest. For example, they might leave him when he's most vulnerable after getting hurt. There could also be themes of self - discovery during his recovery process. As he's dealing with the pain, he might learn more about himself and his own strength.
Well, a frequent theme is the identity of the kidnapper. Sometimes it's an unknown villain, other times it could be a character with a hidden motive. Also, the relationship between the kidnapper and the kidnapped can be explored, such as if there are pre - existing grudges or if it's a case of mistaken identity.