Since I don't have access to the 'si oc saigon bael fanfic', it's hard to determine its main theme. However, often fanfics in general can revolve around the characters' relationships, their growth, or the exploration of a particular world or concept. So it might follow a similar pattern.
Without reading the 'si oc saigon bael fanfic', it's impossible to accurately say what the main theme is. But considering the name, if 'si oc' is a character or place name, it might center around the experiences of that character in Saigon, and 'bael' could be something related to the plot, like a special item or another character, and the theme could be built around these elements.
I'm not sure about the main theme as I haven't read it. It could be about adventure, friendship, or love, like many fanfics.
I'm sorry, I'm not familiar with specific 'si oc saigon bael fanfic'. You can try to search for it on some fanfic websites like Archive of Our Own.
It could be the unique setting of Saigon. The city has a rich culture, history and vibrant atmosphere that can add a special flavor to the fanfic.
It could be a story about the adventures of Si Oc and Saigong in a magical world filled with strange creatures like the Bael. Maybe they go on a quest to find a lost artifact in a forest full of mystery.
I'm not sure specifically which 'Si Oc Saigon Fanfic' are popular. You could try searching on fanfic websites like Archive of Our Own. There might be some unique stories related to it there.
First, we can start with introducing the characters Si Oc and Saigong clearly. Then, introduce the concept of the Bael. Maybe Si Oc has a personal vendetta against the Bael because they attacked his village. Saigong, being the older and wiser one, tries to guide Si Oc in the right way to face this threat.
There could be an OC that is a bit of an outcast in the Bael family but has a heart of gold. This type of character often appeals to readers. They might have a special power that they keep hidden at first. In fanfictions, they could start off as a loner but then gradually become an important part of the story, forging new relationships and changing the dynamics within the Bael family and the broader Highschool DxD story. Their journey from being an underdog to a hero - like figure could make them a popular OC.
One common theme is power struggles. Since the Bael family is known for its power in the Highschool DxD universe, fanfictions often explore how different OCs within the Bael family vie for more power, whether it's political power within the devil society or more magical and combat - related power. Another theme is loyalty. OCs might have to decide where their loyalties lie, whether it's with their family, a particular faction, or a group of friends.
I'm not entirely sure as 'si oc cooler fanfic' is rather unclear. It could potentially be a fanfic (fan - created fiction) related to a self - insert (si) in a story involving overclocking (oc) and a cooler. But without more context, it's hard to say for sure.
One of the common themes is exploring Vegeta's character in depth. The si oc can be used as a tool to understand Vegeta better, like his motives, his pride. Also, the theme of self - discovery for the si oc is often present. As they interact with Vegeta, they learn more about themselves.
Typically, in 'si oc saigong dxd fanfic', there might be a self - inserted original character (oc). This character often has unique abilities or personalities. And it's set in the 'DxD' universe, so it may involve the world - building, magic systems, and character relationships from the original series.