The character interactions are the most interesting. Seeing Phineas and Ferb's wacky inventions interact with the magical and adventurous world of DuckTales is really cool. For example, their super - complex roller coaster might end up in Scrooge McDuck's money bin.
A lesser - known but really cool fanfic is 'DuckTales - Phineas and Ferb: The Merge'. It starts with a strange scientific accident that brings the two sets of characters together. The author does an excellent job of writing the characters true to their original personalities. The boys' constant quest for fun and the ducks' pursuit of treasure make for a very engaging read. It also has some great illustrations that add to the overall charm of the fanfiction.
Well, it could be that Phineas and Ferb accidentally stumble into the Matrix world while working on one of their crazy inventions. Maybe they think it's just another wacky dimension they've discovered. They might start trying to build something to get out, using their usual creative skills and the strange technology they find in the Matrix.
It could be an evil wizard who wants to capture the phoenix for its powerful magic. The wizard might be jealous of the phoenix's ability to be reborn from its ashes and wants to harness that power for his own dark deeds.
Well, the plot could involve the phoenix taking Phineas and Ferb on a journey through different mythical realms. They visit places like the land of flying islands or the underwater kingdom of mermaids. During this journey, they face various challenges that require both their scientific knowledge and the phoenix's magic to overcome. And of course, they have a lot of fun adventures and make new friends along the way.
In a 'Phineas and Ferb meet Zak Storm' fanfiction, it could start with Zak Storm's ship getting caught in a strange storm that sends them to the world of Phineas and Ferb. The two groups meet and are initially confused. But then they discover that they can learn a lot from each other. Phineas and Ferb show Zak Storm and his crew how to have fun in their own unique way, like building a giant waterslide in the middle of town. Meanwhile, Zak Storm tells them about his seafaring adventures and the magic that exists in his world. Eventually, they have to work together to get Zak Storm's ship back to his world. Ferb might use his skills to repair any damage to the ship, and Phineas could come up with a way to create a portal to send them back.
Fanfiction in the DuckTales meet DuckTales context contributes by keeping the fandom active. Fans can discuss and share their fanfictions, which creates a community. It also helps in the evolution of the fandom. New interpretations of characters and concepts can inspire other fans, even the creators of official DuckTales content. It's like a big brainstorming session for the whole fandom.
Candace could be a main character. Since Ferb is sick, she might be in a bit of a dilemma. On one hand, she still has her urge to bust Phineas if he does something out of the ordinary while taking care of Ferb. But on the other hand, she also cares about her brother and might be more lenient or even helpful.
Well, one interesting idea could be crossovers within the DuckTales universe itself. For example, different versions of the characters from various episodes or story arcs meeting and having to work together. Another idea might be the exploration of relationships that were not fully developed in the original series. Fanfiction could delve deeper into the friendships or rivalries between the ducks. Also, new adventures in uncharted locations in the DuckTales world can be a great concept. Writers might send the characters on quests to mysterious islands or forgotten realms that add new layers to the already rich DuckTales lore.