Another plot could involve Kaidou finding out about Saiki's powers by accident. At first, he's in shock but then realizes they can use these powers for good, like helping the school win a big competition against a rival school. They start training together in a comical way, with Kaidou trying to come up with strategies that work with Saiki's powers.
Nendo could be a great addition. His simple - minded nature can add a lot of humor. For example, he could misunderstand the relationship between Saiki and Kaidou and try to get in on their 'adventures' in a really clumsy way.
The Saiki K manga ended. It wrapped up the storylines and gave a satisfying conclusion to the readers. Although it's over, it still holds a special place in the hearts of fans.