Where can I find Marianne vi Britannia light novels?

I'm not specifically familiar with 'Marianne vi Britannia' light novels. It could be a rather niche or new series. You might try searching for it in specialized light novel databases or forums to find out more about popular ones in this category.

Some dedicated anime forums might also be a good place to look for Code Geass Lelouch vi Britannia fanfics. For example, Anime-Planet has a community section where fans might share or recommend their favorite fan-written stories. Additionally, Reddit has subreddits related to Code Geass where you can ask for fanfic suggestions.

You can try looking for it in local comic book stores. They usually have a good selection of graphic novels.

Another option is to check on social media platforms. Sometimes fans share links to their favorite fanfics. For example, on Tumblr, there might be groups or pages dedicated to 'bog and marianne' where they post fanfic recommendations or even host their own fan-written stories.

Some smaller, niche fanfic communities or forums dedicated to related fandoms might also have 'euro britannia oc fanfic'. You can try searching for relevant groups on social media platforms and see if they share or host such fanfics.

Fanfiction.net is also a good place. There are many different stories about them there. However, the quality may vary, so you might need to do some sorting. But it's definitely worth checking out.

One common theme is alternate universes. Writers like to explore what would happen if certain events in the original series had gone differently. For example, what if Lelouch had made different choices during his battles or negotiations.

Fanfiction.net is also a good place. There are many writers who contribute to the Arcane fandom there. However, the quality may vary, so you might need to skim through a few stories to find the really good ones about Caitlyn and Vi.

Another place to look is FanFiction.net. It has a wide range of fanfics including those about Vi and Caitlyn. However, the quality can vary, so you might need to read a few summaries before choosing one to read.

You can try looking on some popular fanfiction websites like Archive of Our Own (AO3). There are a large number of fanfics there, and you can search specifically for 'caitlyn x vi' fanfic. Just type in the relevant keywords in the search bar and you'll be presented with a list of available stories.