Based on your query, I would recommend using Questionwell AI. This platform uses artificial intelligence to generate questions based on provided material, including videos. This means you can input a YouTube video and the platform will generate a set of questions based on the content of the video.

The Question Generator feature allows you to choose the topic, language, and question type (multiple choice, fill-in-the-blank, or short answer). This could be particularly useful for creating a case study based on a YouTube video, as you can tailor the questions to suit the specific learning objectives of the case study.

Additionally, the Question Bank feature extracts essential questions and learning objectives from the input text and aligns them with the generated questions. This could help you ensure that the questions generated are relevant and aligned with the learning objectives of the case study.

Finally, the Export feature allows you to export the questions to various platforms such as Canvas, Quizziz, Quizlet, Kahoot, Blooket, Gimkit, Moodle, or Doc. This could be useful for sharing the case study and questions with your students.

In conclusion, Questionwell AI could be a powerful tool for creating a case study and questions based on a YouTube video.