Son Goku is the cheerful "Monkey King" who uses a staff, known as the Nyoi-Bo, as his primary weapon. There is no explanation given in the anime as to the origin of Goku's weapon; in the manga, it is revealed that the Nyoi-bo was sealed in a canister in the temple, which he and Gojyo shattered whilst goofing off. He is the Seiten Taisei, the Great Sage Equaling Heaven, and whose true self and powers are released when his diadem is removed. As the Seiten Taisei he is very destructive and cruel, and nearly invincible. He's even able to take in the Earth's energy and regenerate because he was spawned from the sheer energy of the earth itself. During Saiyuki Gaiden, Goku was made a ward of Konzen and befriends both Tenpou and Kenren. When his diadem was removed, Goku killed many celestial beings in his craze. Konzen, Tenpou, and Kenren work to protect Goku, but all four became banished from Heaven. Goku was locked in cage high in the mountains and lost his memories. Goku is found by Sanzo and freed from his imprisonment, and Sanzo becomes something like a foster father to Goku. Goku accompanies Sanzo on his mission to track down Hakkai, and helps to prevent Hakkai from killing himself, and Hakkai later becomes his teacher. Goku joins Sanzo, Hakkai, and Gojyo to stop the resurrection of Gyumaoh, during which he discovered that he was Seiten Taisei, having previously been aware of it.