Kim Gyo-gak
Kim Gyo-gak (김교각, 金喬覺, 696-794), or Jin Qiaojue in Mandarin, was a Buddhist monk believed to be the manifestation of Ksitigarbha at Mount Jiuhua, one of the four sacred mountains of Chinese Buddhism, located in Anhui province, China.
Kim Gyo-gak was a Silla prince, who became interested in buddhism when visiting the Tang China. He became so obsessed that he turned himself into a monk after returning to Silla. In 719, he returned to China to cultivate himself at Mount Jiuhua. He died in 794 in Mount Jiuhua, at the age of 99. The monks there believed that Ksitigarbha was reincarnated in him.Mount Jiuhua thereafter became the sacred site of Ksitigarbha and one of the four sacred mountains of Chinese Buddhism.
...
Wikipedia