Skill

Skills are what abilities magical, physical and otherwise are called in this world. The effect of these skills are wide ranging. They can be practical, such as cleaning, constant use, such as improving perception, combat and other various things.

Some skills can be learned. Others are innate to specific species. While others yet are specific to an individual.

Ultimate skills on the other hand seem to be unique in the world and may only exist in a single individual at a time. These ultimate skills with time, some seem to be able to develop a consciousness of their own.

Combining and Evolving Skills
Skills will also evolve with practice and the level of the individual. As an individual levels up and evolves so will their associated skills. This is the most basic way of improving one's skills.

If there is sufficient knowledge and proficiency of specific skills they can be combined for form new and better skills. Those with the Sage, Great Sage,Wisdom King Raphael, or Ciel: Manas (God’s Wisdom Core) can have their ability manage the combination and evolution of skills.

The combination of a Sin Series and a Virtue Series Ultimate Skills will result in a God Skill. This occurs with Void God Azatoth and Ice God Cthulhu.

Rimuru discovered that Naming and Ultimate Skill caused it to evolve into a God Skill.

Categories
Of the Ultimate Skills there are two special series that encompass the most powerful/special skills: The remaining skills are categorized as follows:
 * Sin Series
 * Virtue Series
 * Basic Skills
 * Daily Skills
 * Extra Skills
 * Species Skills
 * Battle Skills
 * Unique Skills
 * Ultimate Gifts
 * Ultimate Skills