Name: Ryukotsusei
Race: Dragon Demon
Role: Dormant Demon
Age: Ancient
Personality: Evil
Weapon/Ability: Strength, Lightning And Strongest Skin On Earth
Description: Ryukotsusei is an extremely powerful dragon demon that has a mask in his forehead that speaks, and who's skin is stronger than anything on Earth. Many years ago, Ryuukotsusei fought with InuYasha's father. During the battle, InuYasha's father was able to seal Ryukotsusei to a cliff with his claw. The wounds InuYasha's father received from Ryukotsusei during the battle, however, is what eventually killed him.

Fearing more demonic transformations, InuYasha goes to see Totosai to see if he can make Tetsusaiga lighter. As a last resort, Totosai tells InuYasha to kill the dormant Ryukotsusei. Before InuYasha is able to kill the dormant demon, Naraku found out about the plan and reawakened Ryukotsusei.

During the very heated battle between InuYasha and Ryukotsusei, InuYasha was able to perform the Backlash Wave against one of Ryukotsusei lightning blasts which created several tornado like attacks that ripped Ryukotsusei's to pieces.

Because the battle, InuYasha discovered that not only is the Tetsusaiga lighter in weight, but that he could also create a Wind Scar at will with it.