Sinon from Ggo could also be very interesting. If she were to enter Sao, her sniper skills might translate in unexpected ways. She could be paired with characters from Sao and learn new combat techniques while also teaching them about the precision of long - range attacks.
Ruby. She has that innocent and curious nature which would make her reactions in the SAO world really interesting. She could be fascinated by the virtual world and its different rules, and her positive attitude might be a source of hope for the other characters. Also, her scythe - using skills could be adapted in the SAO combat scenarios in unique ways.
I think Naruto and Kirito would be an interesting pair. Naruto is all about his exuberant and determined personality, always believing in his strength and the power of friendship. Kirito, on the other hand, is more of a lone wolf type at first but also has a strong sense of justice. Their meeting could lead to some great character development for both. Naruto could teach Kirito about the value of relying on others more, and Kirito could show Naruto some advanced combat strategies that he has learned in SAO.
Ross could be really interesting. Since he's an archaeologist, in a crossover with a show like 'Indiana Jones' (in a fanfiction sense), he could go on an adventure with Indiana Jones. Ross would bring his academic knowledge while Indy would have the practical experience. Their interactions would be filled with Ross trying to over - analyze everything and Indy just wanting to get the job done.
Chiaki Nanami could be an excellent choice. She is the Ultimate Gamer, so if you cross her with a digital or virtual world, there are so many possibilities. She could use her gaming skills to navigate through a new digital realm, like a Matrix - like world. Her calm and intelligent nature would also make her a great character to lead the group in a crossover situation. She could figure out the rules of the new world quickly and help the others adapt.
One idea could be that the main characters from Sao end up in Ggo due to a strange glitch in the virtual world systems. They have to adapt to Ggo's different rules and combat styles while also trying to find a way back to their own world in Sao.
I think a pairing between Klein and Togusa could be fascinating. Klein's more laid - back nature compared to Togusa's by - the - book style could lead to some interesting interactions. And they could both bring different skills from their respective worlds when facing challenges in a crossover situation.
Frisk could be a very interesting character to focus on. Frisk has the power of determination, which could be used in unique ways in the FNAF setting. They could befriend some of the animatronics, using their kindness and determination. Also, since Frisk is the player - controlled character in Undertale, it would be interesting to see how they adapt to the more dangerous and unpredictable world of FNAF.
Kuroko himself would be very interesting. His unique 'phantom' style of playing basketball could create some really unexpected scenarios in a crossover. For example, if he were in a crossover with a detective story, his ability to be unnoticed could be used to solve mysteries in a very unorthodox way while still having some basketball - themed elements in the story.
Ainz Ooal Gown would be a very interesting character to focus on. He has a complex personality and his vast power makes him stand out. In a crossover, seeing how he adapts to a different anime world's rules and cultures would be fascinating. He could be the catalyst for many interesting plot developments.
Lavon Hayes could also be interesting. He's a well - loved character in Bluebell. His leadership skills and big - hearted nature could be put to the test in a crossover. Maybe he has to lead the town in a joint effort with characters from another show during a crisis.