OVA
Description
Ni Jenyi, also known as Ukoku Sanzo, is a complex antagonist within the Gensomaden Saiyuki narrative. He operates under the alias of Dr. Ni Jianyi, posing as a brilliant but disheveled scientist who is the only human residing in Houtou Castle. In this guise, he is instrumental in assisting Gyokumen Koushu with her experiments to revive the demon lord Gyumaoh. His appearance deliberately effaces the dignity of a Sanzo priest, with spiked hair, stubble, and a shabby white coat.

His true identity is that of Ukoku Sanzo, one of the five highest-ranking Sanzo priests and the keeper of the Tenchi Kaigen scripture known as the Muten Sutra. His background is marked by a sharp departure from a privileged, academic upbringing. Born into a wealthy family of professors, he earned a doctorate at a young age but abandoned his scholarly path to become a Buddhist monk. He began training as an apprentice monk named Kenyuu under the master Godai Sanzo. After murdering Godai, he succeeded to the title of Sanzo priest and was given the name Ukoku by Koumyou Sanzo. He traveled with Koumyou for a year before embarking on a solitary, wandering journey.

Ukoku Sanzo is defined by an inscrutable and manipulative personality. He rarely reveals his true intentions, maintaining an air of mystery. He derives amusement from observing the movements of the Sanzo Ikkou and the Kougaiji group, treating their struggles like a game from a distance. Though he often flatters Gyokumen Koushu, he skillfully manipulates her and pulls the strings of events behind the scenes. His motivations are largely self-serving and centered on his own curiosity and enjoyment of chaos, rather than any clear allegiance.

In the story, he is a shadowy figure who orchestrates major conflicts, including assisting in the revival of Gyumaoh and, in the events of Kibou no Zaika, informing Gyokumen about the wish-granting Pearl Jade to set events in motion. His key relationship is with Gyokumen Koushu, with whom he shares a physical relationship while ultimately acting in his own interests. He also has a deep, opposing connection to Genjo Sanzo, observing him as a rival Sanzo.

In terms of development, he is a static yet deeply influential character who remains a calculating observer and puppet master, rarely changing his nature. His notable ability is the power of the Muten Sutra, which can create a darkness blacker than night that buries all creation and nullifies any attacks. Combined with his intellect and his understanding of both science and youkai magic, he is a formidable and unpredictable enemy.