Ultimate Skill

Ultimate Skill (究極能力) is the evolved form of Unique Skill and the final evolutionary stage of Skills in general.

Ultimate Skill Characteristics
Ultimate skills, as the name implies, gives the wielder ultimate power to control the very laws of nature. The only way to counter an ultimate skill is with another ultimate skill. That is the absolute, unbendable rule of the world.

Skills of this class, normally, may not be shared or copied. Only one individual in the universe may own a skill of this class until its current user is either killed or somehow lost the skill in some way.

As the story progresses, it's revealed that through certain methods, ultimate skills can be imparted to others who have not naturally awakened them. The only requirement, like natural ultimate skills, is that the subject must be a spiritual life-form due to the sheer capacity needed to receive skills of this class.

Ultimate Skills
Rimuru Tempest:
 * Azathoth, God of Void
 * Shub-Niggurath, Lord of Harvest
 * Raphael, Lord of Wisdom
 * Beelzebuth, Lord of Gluttony
 * Veldora, Lord of Storms
 * Uriel, Lord of Vow

Veldora Tempest:
 * Faust, Lord of Investigation

Luminous Valentine:
 * Asmodeus, Lord of Lust

Yuuki Kagurazaka:
 * Mammon, Lord of Greed

Chloe Aubert:
 * Sariel, Lord of Hope
 * Yog-Sothoth, Lord of Space-Time

Trivia

 * In the story, the characters pronounce Ultimate Skills using only the being they reference and not the entire names used in the wiki and translations. Meaning, it's "Ultimate Skill Beelzebuth" not "Ultimate Skill Gluttonous King Beelzebuth." This is due to the Japanese texts themselves. (See: Furigana and Ruby Characters)