ONI - VICIOUS DEMONS OF JAPANESE FOLKLORE

 Oni are one of the most iconic figures in Japanese mythology. Their name translated means demons or ogres, and their appearance doesn't differ much from that. They are strong, enormous, and cruel. They are usually portrayed with red skin, horns, and tusks, but their look might be changed depending on the story. Oni are born after a genuinely evil person dies. Then they are sent to Naraka, the Buddhist underworld,  and transform into Oni. They were the army and the servants of the ruler of the underworld - Enma. Their job was to deal out punishment to lesser souls of Naraka. They crushed bones, peeled off the skin, and did much more horrific things to their victims. Most vicious and ruthless souls could transform into an Oni while still being alive. These kinds of demons were the most dangerous and remained on Earth they were terrorizing the living. 

Source: https://youtu.be/B_u3I65lvWQ