I think Sasuke could also be an important character. His cool and brooding personality would contrast with the more light - hearted characters in Cardcaptor Sakura. He could have some interesting interactions with Sakura's friends, like Syaoran. Maybe he would initially be distrustful of the Cardcaptor world but then come to see the value in it. And of course, Syaoran himself could play a major role, especially in relation to Naruto and how they both interact with Sakura.
Definitely Naruto and Sakura Kinomoto. They are the central characters in their respective shows and would be the most obvious choices to lead the crossover story. Their different personalities and abilities would create a lot of interesting interactions. Naruto's brash and determined nature compared to Sakura's more gentle yet strong - willed character would make for great story - building.
A cool concept would be a plot where the villains from both universes team up. Orochimaru from Naruto and Eriol from Cardcaptor Sakura could form an alliance. Then Naruto and Sakura have to work together, along with their friends, to defeat this combined threat. They would have to combine their different powers and strategies, like Naruto's shadow clones and Sakura's use of the Sakura Cards.
Sakura Kinomoto is central to the love story. She is a sweet and energetic girl. Yukito Tsukishiro is someone she has deep feelings for at the start. He is gentle and has a certain charm. Syaoran Li is another crucial character. He is from Hong Kong and is very determined. He starts off not getting along well with Sakura but as the story goes on, their relationship takes on a new dimension in the context of love.
Definitely Naruto himself. He's the main character of the Naruto series, so he has to be there. In a crossover with Attack on Titan, he could meet Eren. Naruto's determination and Eren's drive to protect his people could make for an interesting dynamic between them.
The main characters are Sakura and Syaoran. Sakura is the cardcaptor, a sweet and kind - hearted girl. Syaoran is also involved in the card - capturing world and he has a complex relationship with Sakura which eventually turns into a sweet love.
One popular storyline could be a crossover with Sailor Moon. In this fanfiction, Sakura might team up with the Sailor Scouts to fight a common enemy. Maybe an ancient evil that threatens both their worlds. Another could be a crossover with Harry Potter. Sakura could visit Hogwarts and learn about magic in a different way compared to her Clow Card magic. There could also be a crossover with Pokémon, where Sakura enters the Pokémon world and uses her magic to help in Pokémon battles or to protect the Pokémon from some dark force.
Another concept is that Yugi and his friends discover the existence of the Clow Cards. They team up with Sakura to protect the cards from a new evil force that wants to use them for their own dark purposes. The Yu - Gi - Oh characters could use their unique skills and decks to help Sakura in her battles against the card - related threats.
Definitely Naruto would be a main character. He is the protagonist of the original series and would be the one to drive the story forward in the crossover. Then, perhaps a new character could be introduced who has a special connection to the bone - related aspect. This character could be from another world or a long - lost clan in the Naruto universe. Also, Gaara could be a main character. His sand powers could interact in interesting ways with the bone - related elements, like his sand protecting him from bone attacks or being able to incorporate bones into his sand defenses.
Obviously, Naruto would be one of the main characters. He's the protagonist of the Naruto series and would be the main link to the ninja world in this crossover. Another could be a young Kitsune, maybe one that's just coming of age in the Kitsune world. Their paths cross, and they have to learn to work together.
Obviously Naruto himself would be a main character. He could be joined by Sasuke. In a crossover with 'One Piece', Luffy could also be a main character in the fanfiction, as he is the captain in 'One Piece' and would bring his own unique charm and abilities.
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.