One possible main character could be Boruto's son or daughter. They would inherit Boruto's strong ninja skills and have their own unique personalities. Another could be Sarada's descendant, who might have a combination of the Sharingan and some new, unexpected power. And of course, there could be a descendant of Mitsuki, with his unique snake - like abilities and calm demeanor.
One idea could be a crossover with the 'Dragon Ball' universe. Naruto's descendants could team up with Goku's family to fight a common enemy. Another could be a crossover with 'One Piece', where they sail the Grand Line together in search of a powerful treasure that could change both their worlds. Or perhaps a crossover with 'Bleach', and they battle Hollows and Soul Reapers together in the afterlife.
One idea could be a character from Naruto ending up in the Descendants' world. For example, Naruto himself could be transported there. He might use his ninja skills to deal with the challenges in the Descendants' world, like facing off against the villains in a very different way compared to the Descendants' characters. Maybe he'd use his shadow clone jutsu to confuse the bad guys or his Rasengan to take on powerful foes.
In terms of speed, characters like Sasuke from Naruto are extremely fast. If combined with the agility of a Descendants character like Evie, they could perform some amazing acrobatic feats. Evie could use her knowledge of potions and such to enhance Sasuke's Sharingan abilities further. Maybe she could create a potion that makes the Sharingan more perceptive or gives it the ability to see through certain types of magic.
There's also 'When Descendants Join the Avengers'. This fanfiction focuses on how the Descendants integrate into the Avengers' daily operations. It shows their growth as they learn from the more experienced Avengers. Characters like Carlos become more confident as he takes on tasks with Iron Man, and it's really heart - warming to see their relationships develop.
Power struggle is also prevalent. The characters from Descendants, who are often the offspring of famous Disney villains and heroes, have their own power dynamics. When Maleficent enters their world, there is a new level of power struggle as she is a powerful force herself. This can lead to interesting plotlines where they have to either compete or cooperate.
The character relationships are also very unique. You can have unexpected friendships form, like between the mischievous Loki and the equally sly Uma from the Descendants. Or romances that cross the two universes, which add a whole new layer of intrigue and drama to the fanfiction.
I found a really fun crossover fanfic where the villains from Descendants team up with some of the forgotten villains from Once Upon a Time. It's called 'Villainous Alliances'. It shows how they would interact and form plans to take over both their worlds. The character development in this fanfic is quite good as it gives more depth to the Descendants' villains who might seem one - dimensional at first.
One idea could be a story where the characters from 'Descendants' end up in the 'Twilight' world. For example, Mal could meet Bella and they could form an unlikely friendship. Mal might be intrigued by Bella's relationship with Edward and the whole vampire - human dynamic in the 'Twilight' world.
There's 'Mixed Magics: Harry Potter and Descendants'. This fanfiction delves deep into how the two different magical systems would interact. For example, the use of magic wands in the Harry Potter world versus the natural magic the descendants seem to possess. The plot often revolves around a threat that can only be defeated by combining the powers and knowledge from both universes.