Another plot could revolve around the next generation discovering a long - lost family secret. For example, they find out that there's a hidden talent or special power that runs in the family but has been forgotten over the years. This could lead to all sorts of adventures as they try to understand and master it.
One idea could be that Lincoln Loud discovers a rare and powerful Pokemon in Royal Woods. He then has to keep it a secret from his sisters while training it. Another could be the Loud sisters each getting a Pokemon that reflects their personalities. For example, Lola might get a Jigglypuff because it's cute and girly.
A cool plot for 'the loud house crossover fanfiction' might involve a crossover with 'My Little Pony'. The ponies could come to Royal Woods, and the Loud sisters could be fascinated by their magic and cuteness. Lincoln might have to figure out how to get the ponies back to Equestria while also dealing with his sisters' excitement. Or perhaps the Loud family travels to Equestria and has to adapt to a world ruled by ponies.
One idea could be that Naruto somehow ends up in the Loud House world. Maybe he's on a mission and a strange jutsu goes wrong, transporting him there. He could use his ninja skills to help the Loud siblings out with their daily problems, like getting rid of a bully at school using his shadow clone jutsu.
One idea could be that the Loud family members gain superpowers similar to the Avengers and have to team up to save Royal Woods from an alien invasion. For example, Lincoln could be like Captain America, leading the group with his strategic mind.
Another plot could revolve around a time - travel aspect in the Twilight Next Generation fanfiction. A young character accidentally travels back in time to when their parents first met and starts to interfere. This could lead to all sorts of changes in the timeline and force them to find a way to fix it before they cease to exist in their current form.
One idea could be the next generation facing a new, more powerful enemy that combines the powers of all the previous villains. They'd have to learn from their parents' stories and develop new skills to defeat it.
A plot idea could be that the next generation of Miraculous holders has to team up with some of the old villains' descendants who are now on their side. They have to overcome the prejudice from the public who don't trust them. Together, they work to stop a new evil that is threatening to destroy the balance between the Miraculous powers and the normal world.
One idea could be about a new type of Pokemon that emerges in the next generation. Maybe it's a fusion of two existing types due to some strange environmental phenomenon. Another could be a story where the main character is a descendant of a famous Pokemon trainer from the previous generations and has to live up to their legacy while facing new challenges in the Pokemon world.
Another plot could involve the next - generation Avengers having to prove themselves to the world. The public is skeptical of them at first, thinking they can't live up to their parents' legacies. So they take on a mission to save a major city from a powerful alien invasion, and in the process, they gain the public's trust.
Another plot could revolve around the relationships between the children of the original RWBY characters. For example, if Ruby's daughter has a different view on hunting Grimm compared to her mother. It could lead to internal conflicts within the new team and also show how the world has changed since the first generation's time. There could be political aspects too, like new laws regarding Huntsmen and Huntresses that they have to navigate.