The Demon King (魔王) is the most powerful life form on the continent, and rules The Monster Realm. Ever since the reign of Demon King Ssulal, they have been granted immortality and a fixed ruling lifespan of 1000 years (after becoming Demon King). Demon Kings choose their successors. Once a successor is named, the immortal power is passed from the old Demon King to the successor. If the 1000 year span is up and a successor is still not named, the Demon King will lose immortality, although he/she might remain a formidable creature.
The Demon King has the ability to grant its blood to another creature (human, snail, snake, just about anything), turning it into a Dark Lord (魔人). Dark Lords swear absolute obdience to the Demon King and all its successors. Only 24 Dark Lords can be created.
The calendar system used in the Rance World uses the name of the ruling Demon King to mark the era. The previous Demon Kings, along with the calendar era markings are: