Kaneki and Zero could make an interesting pairing. Kaneki has his inner turmoil with his ghoul side, and Zero has his own battle against his vampire nature. They could bond over their struggles to control their 'dark' sides and their determination to protect the ones they care about.
Ayato and Kaname could be an interesting match. Ayato is a brash and powerful ghoul, while Kaname is a sophisticated and powerful vampire. Their power levels are quite high, and their personalities are so different. It would be fascinating to see how they interact, whether they fight or end up having some sort of mutual respect for each other in the context of a fanfiction.
One great pairing could be Celty and Uta. Celty is a headless rider with a lot of mystery around her, and Uta is a ghoul with a deep love for art and his own brand of mystery. They could share their knowledge of the underground and the strange things they've seen. Another interesting pair would be Shizuo and Ayato. Shizuo's strength and short - temper against Ayato's rebellious and somewhat violent ghoul nature would lead to some intense confrontations. And finally, Izaya and Nishiki could be paired. Izaya loves to play with people's minds, and Nishiki has his own complex relationship with his ghoul identity and his past actions. Izaya could really mess with Nishiki's head in the crossover.
Touka Kirishima and Dean Winchester would be a great pairing. Touka is strong - willed and a skilled fighter as a ghoul, and Dean is a tough hunter. They could have some great banter and action scenes together. Maybe Touka could teach Dean some of her fighting techniques in close - quarters combat, and Dean could show Touka how to use some of his hunting tools.
Harry Potter and Ken Kaneki would be a really interesting pairing. Harry has faced so much darkness in his life and has a strong sense of justice. Kaneki, too, has been through a lot and is trying to find his place in a world that fears him. They could bond over their shared experiences of being different and having to fight against powerful enemies.
One possible plot could be a character from Tokyo Ghoul ending up in the world of Vampire Knight. Maybe Kaneki, with his unique ghoul powers, could interact with the vampires and hunters in Vampire Knight. He might initially be seen as a threat, but as the story progresses, they could find common ground in their struggle for survival in a world that fears them.
Rize from Tokyo Ghoul and Sirene from Devilman would be an interesting pair. Rize is a very powerful and somewhat unpredictable ghoul, and Sirene is a demon with her own motives. They could either be at odds, constantly trying to outwit each other, or they could find common ground in their pursuit of power. Their interactions could be full of tension and mind games, which would make for an exciting part of the fanfiction.
Ichigo and Kaname would be a very interesting pairing. Ichigo is hot - headed and always ready to fight for what's right, while Kaname is more calculating and mysterious. Their different personalities could lead to some great interactions, whether they're clashing or working together. Maybe they could learn from each other's ways of protecting their people.
Akira and Giorno would make an interesting pairing. Akira has his leadership skills and the ability to use Personas, while Giorno has his determination and powerful Stand, Gold Experience. They could learn from each other's sense of justice and different ways of achieving their goals. Akira could teach Giorno about the power of the collective, as the Phantom Thieves work as a team, and Giorno could show Akira how to be more assertive and decisive in his actions.
Definitely Uta from Tokyo Ghoul. His mysterious nature and his skills as a mask - maker would bring a lot of intrigue. Also, Haruka Nanase from Uta no Prince - sama could be interesting. Imagine his pure and kind - hearted personality being exposed to the dark and dangerous world of Tokyo Ghoul. The contrast between them could create some really engaging storylines.
Papyrus and Beast would also make for a great pairing. Papyrus is full of enthusiasm and always wants to do the right thing in Glitchtale. Beast is highly intelligent and has his own moral code. Papyrus could learn a lot from Beast's knowledge, and Beast could be inspired by Papyrus' unwavering optimism. They could work together on scientific projects in the X - Men's labs, with Papyrus bringing his unique perspective and Beast his scientific expertise.
A pairing between Bella from Twilight and Will from Sky High could be really interesting. Bella is used to the world of vampires and werewolves, and Will is a leader - type at Sky High. Their personalities are quite different. Bella is more introverted and brooding, while Will is confident and heroic. They could learn a lot from each other, and their relationship could develop as they face challenges together in the crossover world.