恵果 (746–805) (PY Huiguo; Jpn Keika)
A priest of Esoteric Buddhism in China. As a boy, he became a disciple of Pu-k'ung (Skt Amoghavajra), and in 765 received from him the esoteric doctrines of the Womb Realm and the Diamond Realm. Later he was appointed to serve at the altar of the imperial palace and lived at Ch'ing-lung-ssu temple in Ch'ang-an. He had many disciples. In 805 he transmitted the teachings of Esoteric Buddhism to Kobo, who had come to China and would later found the True Word (Shingon) school in Japan.
Hui-kuo (Chinese: 惠果; pinyin: Huìguǒ; Wade–Giles: Hui-kuo) (746–805) was a Buddhist monk during Tang Dynasty China, particularly in the recently imported Tantric Buddhist tradition from India. Later, he would become the teacher of Kukai, who in turn founded the Shingon school in Japan. Hui-Guo was one of two Buddhist masters at Ximing Temple, the other being the Indian monk, Prajñā. Hui-Guo began his study of Buddhism at age 9, under a senior disciple of Amoghavajra, another Indian monk of the tantric tradition, eventually becoming a direct disciple. By age 20 (766), Hui-Guo was officially an ordained priest and extensively studied the Womb Realm and Diamond Realm Mandalas, before being fully initiated into the esoteric order that same year by Amoghavajra.
In time, Hui-Guo's prominence attracted students from Korea, Central Asia, and even Java, aside from his Chinese students. By 805, Hui-Guo was introduced to the Japanese monk Kukai, who writes of the encounter (emphasis added):
“ As soon as he saw me, the abbot Hui-Guo smiled, and said with delight, "Since learning of your arrival, I have waited anxiously. How excellent, how excellent that we have met today at last! My life is ending soon, and yet I have no more disciples to whom to transmit the Dharma. Prepare without delay the offerings of incense and flowers for your entry into the abhiseka mandalas Womb Realm and Diamond Realm. ”
Hui-Guo began an intensive training of Kukai that finally ended in his death on the fifteenth day of the twelve month (805) by the Chinese calendar. While the tantric tradition largely died out in China, the lineage survived in Japan through the Shingon school founded later by Kukai.