The Legendary Nature Spirits(, Densetsu no Shizenrei) was the term given to the five original embodiments of the natural elements which can either provide foundation for life in the BTUverse or act as the cataylst of its destruction. The spirits are the emobidments of their corresponding elements of FIre, Water, Wind, Earth, and Lightning to a point that they can only be considered true incarnations of their own powers to a pata abstract level. Ages ago, The five spirits decided their presence in the BTUverse was no longer needed and took on 5 mortal disciples to pass on their powers and teachings to throughout the ages.