Hajime Hinata is also a great option. He has a relatable and determined personality. In a crossover, say with a detective - themed world like Sherlock Holmes' London, he could use his deductive skills (which he developed during the events of Danganronpa 2) to solve new mysteries. His journey of self - discovery in Danganronpa 2 could also be further explored in a different setting, as he tries to find his place in the new crossover world.
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.