Nachi looks like Riki-Oh only with longer hair and not as muscular.
His most distiguishing is that he has a scar in the shape of a swastika on his right hand since birth.
He has great resentment towards his brother for abandoning him. He also believes that when humans die they are releived from pain and suffering.
Nachi is gifted with strong psychokinesis, the ability to manipulate, or "communicate with", objects and matter with the mind. The source of these powers is his swastika hand and head.
He is also able to use energy blasts, possibly ki, that can disintegrate human bodies, however Riki-Oh's hexagram scarred hand can deflect these blasts.