Nachi is Riki-Oh's younger brother from whom he was separated they were children. He is known as the "Living God". He appeared in the manga and in the OVA Riki-Oh: The Child of Destruction.
Nachi looks similar to his older brother and even has a scar on his hand, much like Riki-Oh, but has a swastika instead of the Star of David. He is also gifted with telekinetic powers and can heal people.
When they were children, Riki-Oh and Nachi were playing Hide and Seek in a forest, and Riki-Oh was picked up by a family and was adopted. Nachi, who was looking for Riki-Oh, believed that his older brother left him and swore revenge. Many years later, Riki-Oh was on a search for Nachi after escaping prison. Eventually, the two brothers meet and eventually battle, with Riki-Oh emerging as victor and Nachi dying in his brother's arms.