Ryuichi is one of the Demon kings of the underworld and often travels to the mortal realm, often making deals with war generals, and many other government officials in exchange for their souls, he is as old as time itself, and is virtually unkillable, although he is somewhat weak when it comes to fighting. Only having smoke as a weapon, although it can be deadly, with the right tools it is very in effective, and often times he wins battles with pain tolerance and endurance rather than overpowering his opponents. If a limp is cut off, he can reattach it to himself, a thread magically weaving the limb back on.