Ultimate Magic

Ultimate Magic (究極魔法) is a secret magic technique of the Elf Tribe that embodies all of the magic of its user and creates a unique, powerful spell.

Description
This magic technique requires the user to become acquainted with the origin of souls and to physically draw closer to mana. The user is then enabled to embody all of their magic and create a spell that is unique to each individual. These are incredibly powerful spells, capable of combatting mid to high-ranked devils.

The vast amount of magic required for this technique limits it to only the most powerful of elves. However, humans who have learned Mana Method and are capable of True Magic, can borrow magic from natural mana in order to artificially attain Ultimate Magic.

Trivia

 * In the official English translation, Yami Sukehiro mentions that some mages learned to use "ultimate magic" by exploring dungeons. However, Yami uses the term saikyō no mahō (最強の魔法), which is different from the one later used for the elves' magic technique.