Ryu

Ryu is a demonic man who lives on Mount Everest. Ryu is unable to leave Mount Everest. He is the strongest man in the world. Mount Everest is his brother who was transformed into the world's largest mountain to protect the world from Harry Onion. Ryu holds a deep hatred towards Harry Onion. His body was possessed by demons in 1000 because of his rage.

Ryu is the greatest martial artist. He is a master at every art. However, he cannot leave Mount Everest, so he is unable to challenge anyone with his power. People can come to him to challenge him at Mount Everest, but he has not had a challenger since 1315 (Frost Ace).

In 2101, Sans and Harry Onion finally defeat Ryu.

Personality
Ryu is an angry person. He is waiting for his revenge against Harry Onion. Before he was angry, he was short-tempered and quick to decide. However, he did have a soft spot for his family.

Everest
Everest is Ryu's brother. Everest sacrificed his life in order to protect the world from Harry Onion. Everest and Ryu both practiced martial arts, and they were very close. Ryu waits for the day to avenge his brother.

Harry Onion
Harry Onion is the cause for Everest's death. Ryu hates Harry Onion, and is trying to get his revenge for turning his brother into a mountain.