魔王ウル・オーマは、『魔王道』の主人公で、かつて世界を支配した千年前の魔王。神々と勇者たちに敗れた後も魂を完全には消されず、長い封印を経て現世へ復活するが、その肉体は最弱クラスの魔物・コボルトとなっていた。
かつての圧倒的な力は失ったものの、千年前に培った魔道知識、軍略、統治経験、進化の知識は健在。弱い肉体を罠、準備、情報、魔道、進化で補い、野生化した魔物たちに知識や戦術を教えながら、新たな魔王軍を築いていく。
「進化樹形図（ソウルツリー）」を利用して自らの進化を操り、コボルトから狼頭人、さらに巨大な黒狼「死毒の邪狼（デスヴォルスト）」へ進化するなど、戦闘でも知略と応用力を発揮する。また、契約を重んじる「悪魔との契約」や、人間の負の感情を力に変える「悪魔の馳走」など、魔王らしい特殊能力も持つ。
尊大で冷徹、合理的な支配者でありながら、契約や庇護には非常に律儀。小柄で愛嬌のあるコボルトの外見と、神々ですら消し去れなかった古代の魔王としての威圧感。その強烈なギャップが、ウル・オーマ最大の魅力である。
Demon King Uru Ouma is the protagonist of Maou-dou and a former ruler of the world from a thousand years ago. Even after being defeated by the gods and their chosen heroes, his soul could not be completely destroyed. After a long period of imprisonment, he eventually returns to the world of the living, only to find himself reborn in the body of a kobold, one of the weakest types of monsters.
Although he has lost the overwhelming power he once possessed, his knowledge of magic, military strategy, governance, and evolution remains intact. He compensates for his frail body through traps, preparation, information, magic, and carefully controlled evolution, while teaching feral monsters tactics and knowledge in order to rebuild a new Demon King’s army.
Using the Evolutionary Tree, or Soul Tree, Uru can deliberately guide his own evolution, progressing from a kobold to a werewolf and eventually into the massive black wolf known as the Death Vorst. He also possesses distinctly demonic abilities such as Devil’s Sign, which revolves around binding contracts, and Devil’s Malice, which converts the negative emotions of humans into power.
Uru is arrogant, cold, and highly rational, yet he is also remarkably strict about honoring contracts and protecting those under his rule. The striking contrast between his small, almost endearing kobold appearance and the intimidating presence of an ancient Demon King whom even the gods could not fully erase is one of Uru Ouma’s greatest appeals.
