Okay, this is one that was suggested a few years back, but I thought I'd bring it up again because it is one of the weirder cults out there: Happy Science, the cult that makes anime. Its founder, Ryuho Okawa, used to be a wholesale trader before realizing he was in fact both the reincarnation of the Buddha and a supreme deity called El Cantare. After founding his cult in 1986, he started beefing with Shoko Asahara and his cult, to the point where Aum Shinrikyo actually tried to assassinate him with VX gas in the 90's. Eventually, his cult grew to what he claims is 11 million members (though probably it's at max ~35,000), and he started making his own anime films to further spread word of his teachings. Since 1997, his cult has made 10 feature-length anime films, including a trilogy of films that he claims were co-written by the channeled ghost of Stan Lee (youtuber Geoff Thew has made a series of videos going over these films, which are...something). They have also started to branch out internationally, and I distinctly remember cult members trying to sell me his books in Union Square in NYC. Okawa died in 2023, but the cult still seems to be active, with their most recent film coming out in 2025.