I just read a great theory from Tebow's Youth Group about the real final villain being the person that tempted Kaguya to eat the fruit of the shinju, Sojobo Tengu. Although the theory is plausible, I thought of something. The series is almost over, isn't it too late to bring new characters into the story?
Even though his existence was hinted at, only people like us on forums who take the time to analyze the backgrounds and story would have caught on. The common Japanese reader (who Kishi is trying to appeal to) most likely does not look for the same hints that we do. My point is, it would seem too random to the average person, and might turn people off from the story because a random person is revealed to be the mastermind.
What do you guys think?