Where Can I Find Erza And Jellal 100 Year Quest Crossover Fanfiction?

Finding good stuff for that specific crossover can be like hunting for a rare pairing in a tiny fandom—you gotta know where to look and be patient. Honestly, I don't think there's a huge amount out there that explicitly merges 'Fairy Tail's 100 Year Quest' with Erza and Jellal stories, so you're dealing with a pretty niche request. Your best bet, honestly, is to go straight to Archive of Our Own and use their tag filtering system. Start with the 'Fairy Tail' fandom tag, then add 'Erza Scarlet/Jellal Fernandes' as the relationship, and then maybe try the '100 Year Quest' character tag or add '100 Year Quest' as an additional tag. The search system there is powerful, but you have to play with it—sometimes you'll find fics tagged with just 'Fairy Tail' that are set post-canon and might actually be Quest-era stories.

Another tactic I've used is to search on FF.net by filtering for the 'Fairy Tail' category, then reading summaries manually. It's more tedious, but sometimes writers there don't tag meticulously. Look for fics updated after the Quest manga started, or ones that mention 'post-Alvarez' or 'post-war' in the summary; a lot of those will naturally incorporate the new quest setting. I remember finding one decent longfic that way, where the author had Jellal joining the quest crew as a sort of external ally, and the dynamic was pretty solid. It wasn't explicitly a crossover with another series, but it was set wholly within the 100YQ timeline, which is half of what you want. Sometimes you have to compromise on the 'crossover' part unless you're specifically looking for them to hop into, like, 'One Piece' or something.

If you're open to it, don't sleep on Tumblr or Twitter either. A lot of writers post snippets or links to their works on those platforms using specific hashtags like #ft100yq or #jerza. You can sometimes ask directly in those communities for recommendations, and someone might point you to a personal blog or a Google Doc. The community is smaller, so the signal-to-noise ratio is better, but the quality can be hit or miss. I've had mixed luck—some amazing short pieces, some that felt rushed. It really depends on the day.

AO3 is definitely the prime spot. Filter by the 'Fairy Tail' fandom, then add the 'Erza Scarlet/Jellal Fernandes' relationship tag. After that, you can try adding '100 Year Quest' as a freeform tag, but honestly, there aren't many. I'd suggest just browsing the Jerza tag sorted by 'Date Updated' and reading summaries for anything posted in the last few years—most new fics will assume the 100YQ timeline anyway. Crossovers are even rarer; you might need to search a secondary fandom tag and hope someone double-tagged it. It's a bit of a slog, but I found one where they end up in the world of 'Edens Zero' that way.