1536 - 1643
Appearances: Onimusha (Shin)
Tenkai was a 天台 Tendai Buddhist monk who came from the temple of 寛永寺 Kan-eiji. He was famous for being a 黒衣の宰相 Kokui no Saishou (Priest who also became a minister), since he served as an advisor for the three generations of Tokugawa: Ieyasu, Hidetada and Iemitsu. His posthumous title is 慈眼大師 Jigen Daishi.
There are some sources that said an Akechi clan member survived the loss at Yamazaki and then went on to disguise as Nankôbô Tenkai, however this is not true, and is just a tale.