What is a trilogy of 9 called?

Excuse me, could you please clarify for me? I'm a bit confused by the question "What is a trilogy of 9 called?" Typically, the term "trilogy" refers to a set of three related works, whether it's in literature, film, or some other medium. So, the idea of a "trilogy of 9" doesn't quite fit the conventional definition. Are you perhaps referring to a series of nine works that are somehow interconnected? Or is there a specific context or cultural reference that I'm missing? I'd appreciate it if you could elaborate further on your question.