Ultimate Skill

Ultimate Skills (究極能力) are the successor to Unique Skills and the final evolutionary stage of Skills in general.

Characteristics
Ultimate Skills, as the name implies, grants its wielder the ultimate power to control the very laws of nature. The only ways to counter an Ultimate Skill are with another Ultimate Skill, God Grade Equipment or Divinity. That is the absolute, unbendable rule of the world.

If Unique Skills are born from one's individuality, Ultimate Skills are born when Unique Skills are brought past their limit. That is why no Ultimate Skill is identical. A strong will and Soul, as well as being a Spiritual Lifeform are necessary to awaken an Ultimate Skill. Similar to all Skills, a large amount of Energy is consumed and converted to awaken them.

Through certain methods, Ultimate abilities can be imparted to those who have not naturally awakened them. One of the requirement is that the recipient must be a Spiritual Lifeform to qualify for it.

Variation
Variations of Ultimate Skills based on how they are acquired exists, namely Ultimate Gifts and Ultimate Enchantments. Ultimate Gifts denote to Ultimate Skills which are given through a Soul Corridor, while Ultimate Enchantments are those without it. There seems to be no difference in power between Ultimate Skills, Ultimate Gifts, and Ultimate Enchantments.

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 Lord of Gluttony Beelzebuth." This is due to the Japanese texts themselves. (See: Furigana and Ruby Characters)