The Lord Ohma, also know only as Ouma, or Ouma, the Spirit of Vengeance, (Voiced by: Akio Ōtsuka in the original Japanese dub and Paul Oddo in the ADV English dub) is the final ghost fought in the series. He appears in Episode 20, Farewell, Amanojaku... The Arrival of Ohma, returning to take revenge on Satsuki for his multiple instances of imprisonment in the past by her family. He holds a hateful grudge against Kayako Miyanoshita and the Miyanoshita family. The first thing he did after he was freed of his spiritual sleep was go after Satsuki and Keiichirou.The only way to seal him away was to imprison him in a huge bell once the exorcist has enough spiritual power. Satsuki and the gang decide to use the old school's bell, but since Satuski hadn't developed her spiritual powers at that time, Amanojaku left Kaya's body to fight with Lord Ohma while Satsuki gathered power. In the end, Satsuki seems to have sealed both Ohma and Amanojaku. He was the last and most muscular ghost to be presented.
Ohma is a massive, imposing monstrous humanoid, with skin and claws made of rock. His head and ugly features appear like roughly carved, faceted stone. He has bright blue eyes with slit-like pupils and jagged, sharp yellow teeth. He has huge, stony forearms and a a spiked Ankylosaur-like tail.
Ohma has powers over stone and earth elements, able to create enormous splits in the Earth's crust that expose lava. It is also explained in the Ghost Diary that Ohma's revival also awakens every other ghost that had been put to sleep controlled under his power. Ohma also has the ability to possess and control scores of humans as Satsuki's class and teacher come under his power, luring Satsuki and Keiichirou into the Old School. In these ways it is arguable that Ohma is among the most powerful ghosts that Satsuki faces.