Brief summary of some more random info on Matara-jin - again, I'm not saying they have to figure in Touhou 16 at all, but it breaks down what his deal is:Origin: Ennin was one of the important Buddhist monks who studied at Tang China. During his voyage back to Japan, he heard Matara-jin calling out to him. His sect would establish Matara-jin as the patron of 常行三昧堂 (JP: Jōgyō-zanmai-dō) - a hall for mystic training, and 玄旨帰命 (JP: Genshi Kimyō) - a Tantric rite of initiation. All in all, he was supposed to be a hidden god not shown to the public.As patron of the performing arts:This also makes him the patron of ushirodo, the space at the rear of the temple complex. Among other purposes, the ushirodo was used for Noh and related theatrical performances. This should be why Matara-jin became a patron of the performing arts associated with the Hata clan.Connection with Silla Korea:Ennin frequently associated with and learned from monk scholars of Silla during his stay in China, especially when at 赤山法華院 (CN: Chishan Fahua-yuan), a temple in today's Shandong Province founded by a Silla general. In his true nature, Matara-jin might simply be adopted from their local worship.Explanaining his role as Yama's secretary:Said local god is often explained to be 泰山府君 (CN: Taishan Fujun; JP: Taizan Fukun), god of Mount Taishan in Shandong, one of the most important mountains in Chinese culture. The notion of this god appeared around 200 CE under the influence of Buddhism, as patron of the boundary between the living and the dead. The god was highly popular with rich Taoist and folk lore appearances, and played an important role in the wizardry of Abe no Seimei.(Mount Tai and Taishan Fujun also have a strong connection with the Big Dipper.)As a merger of Daikokuten and Dakini , hermaphrodite, god of eroticism, etc.:The Genshi Kimyō rite would absorb increasingly more elements of Tantric eroticism, leading to its banning as an evil cult in mid-Edo era, and the burning of its books.EDIT:By the way, I forgot about mentioning the biggest connection. It is common Chinese lore that the direction of the Big Dipper's handle indicates the four seasons. In spring it points east, in summer south, and so on. This is something you might be taught in elementary schools.EDIT2:I also haven't reported on July 14's Nikenme Radio stream. In short:- ZUN couldn't guarantee the downloadable demo be released at the usual time. This is why we haven't seen the demo.It will make you feel uneasy, maybe creep you out. You will see it from the artwork of the fourth boss.