What are some interesting crossovers in Phineas and Ferb Avengers fanfiction?

One idea could be to explore what happens when Phineas and Ferb build a time - traveling device. They could go back in time and meet their parents when they were kids. Another idea is a story where Perry the Platypus has to team up with Doofenshmirtz's daughter Vanessa to save the day. Maybe they discover a new villain who is more powerful than Doofenshmirtz and they have to put aside their differences to stop this new threat.

A cool Phineas and Ferb fanfiction idea is where they build a machine that can swap personalities with the other characters. So Phineas becomes Perry the Platypus for a day and has to do his secret agent duties, while Perry has to come up with wild inventions with Ferb. It's a fun way to see the characters in different roles and how they would handle the new situations. There are also fanfictions that expand on the relationship between Doofenshmirtz and his daughter Vanessa, and how the events in Phineas and Ferb's world affect them.

Another interesting OC could be a time - traveling character. This OC could accidentally land in the Phineas and Ferb's world while on a mission in time. Their presence could cause some chaos as they try to fix their time - traveling device, and Phineas and Ferb might end up helping them, leading to an adventure through different eras.

One idea could be a crossover with 'Kim Possible'. Phineas and Ferb could use their inventive skills to help Kim in one of her missions against Dr. Drakken. Maybe they create some high - tech gadgets for her. Another idea is a crossover with 'The Simpsons'. The boys could visit Springfield and get involved in some wacky adventures with Homer and Bart. They might even build an amazing contraption in the Simpsons' backyard.

The OC could be a time - traveler from the future. She comes back to the present to stop an event that will have a negative impact on the future. Phineas, being the curious and adventurous type, joins her on this mission. They use their combined creativity and Ferb's logical thinking to solve the mystery and prevent the disaster.

One interesting plotline could be how Phineas and Ferb deal with the aftermath of getting busted. Maybe they have to find a way to convince their parents that their wild inventions were actually for a good cause. Another could be that their friends rally around them to help prove their innocence.

One idea could be Perry having to navigate the human world while still trying to keep his secret agent identity hidden from Phineas and Ferb. He could end up getting a regular job as a human and have all sorts of comical misunderstandings at work.

One idea could be Phineas and Ferb building a time - traveling roller coaster that takes them to different eras in their town's history. They could meet their ancestors and see how things were built and developed. Another plot could be that Doofenshmirtz creates an invention that accidentally swaps the personalities of all the characters. So Phineas becomes super - serious and Ferb becomes overly enthusiastic. It would be really funny to see how they deal with their new personalities while still trying to complete their daily big builds.

Well, Doofenshmirtz and Loki make an interesting pair in some fanfictions. Both are villains with a certain charm and a penchant for elaborate plans. They could scheme together to take over their respective worlds or cause chaos. Also, Perry the Platypus and Black Widow are a fun pair. Perry's stealth and combat skills can be compared to Black Widow's spy and fighting abilities. They could team up to take on their enemies, with Perry using his platypus - specific moves and Black Widow her martial arts and gadgets.

The character interactions are also fascinating. Picture Naruto trying to explain ninjutsu to Phineas and Ferb. Or Isabella being amazed by Sakura's strength. These crossovers allow for a lot of humorous and heartwarming exchanges between the characters from the two very different shows. Another interesting part is how the fanfiction writers often have to create a new kind of logic to make the two worlds coexist. For example, how the technology in Phineas and Ferb's world might interact with the magic - like chakra in Naruto's world. It's a creative challenge that often leads to some really cool and innovative story ideas.