Some 'vicious x spike fanfic' may focus on their power dynamics. Given that both characters likely have their own strengths and abilities, a fanfic could explore how they compete or cooperate in a situation where power is a crucial factor, like in a battle for territory or resources.
There could be 'vicious x spike fanfic' that delves into their backstories and how those past experiences shape their interactions in new and interesting ways. For example, a story might reveal a shared trauma that they both have but deal with differently, and through that, they start to understand each other better.
There are 'spike x mane six fanfic' that focus on Spike's growth. For example, in some stories, he teams up with Rainbow Dash. They have races and Spike learns about determination from her, which is really interesting.
Ask in relevant fan communities. There are often groups dedicated to the fandom that these characters belong to. Members can recommend their favorite 'vicious x spike fanfic' based on their own reading experiences. They might also be able to point you to specific authors who are known for writing great stories about these characters.
The idea of a 'Buffy Spike sperm baby' fanfic is quite out there. Most Buffy fanfic communities focus on the characters' development, their battles against evil, and their complex relationships. For example, there are many fanfics that deal with how Buffy and Spike's relationship evolved over time, from enemies to something more. But the specific concept you mentioned is not a common or widely - promoted one within the Buffy fanfic world.
One popular Spike fanfiction could be those that explore his backstory in more depth. For example, stories might focus on his early days as a vampire and how he became the character we know. Another popular type might be ones where he has a romantic relationship with a different character from the original series, like Spike and Willow getting together in an alternate universe.
One popular theme is the redemption of Spike. Fans often explore how he can move from his villainous past to become a more heroic figure, especially in relation to his relationship with Buffy.
There may be some popular 'evil spike mlp fanfic' stories, but it really depends on the different fan communities. Some might be popular within a specific group of fans who are really into exploring darker themes in the MLP world. However, without extensive research in the various MLP fanfic platforms, it's difficult to name any in particular. Usually, if a story has a really engaging way of portraying Spike's transformation into an evil character and how it affects the rest of the ponies, it has a better chance of being popular.
One popular 'spike and reader fanfiction' might be those that explore Spike's complex character in relation to the reader. For example, stories where Spike and the reader go on adventures together in the dark and dangerous world of their fictional universe. Another could be ones that focus on the emotional connection between them, like how Spike overcomes his past traumas with the help of the reader.
There are various types of Spike the Dragon fanfictions. Some focus on his past, like how he came to be with Twilight. Others might be comical, such as Spike accidentally causing chaos in Ponyville while trying to do something good. And then there are the more emotional ones, where Spike has to deal with feelings of loneliness or not being fully understood by the ponies around him.
There could also be a plot where Spike starts to develop feelings for Ember, but he's hesitant because of their different species and backgrounds. Ember, on the other hand, might not be aware of Spike's feelings at first. This creates a lot of internal and interpersonal drama as they navigate their relationship.
Well, there's a 'spike x harem fanfic' where Spike finds himself in a magical world and attracts a diverse group of characters to his side, forming a harem. In this fic, his relationships with each member of the harem are explored in a unique way, like how he has to balance his time and attention among them. It's really engaging as it shows different aspects of his personality through these interactions.