Heavenly Spiritual Roots were extraordinarily powerful, but they were so rare that an immortal cultivation sect might discover only one every few hundred years.
Another kind, the Mutant Spirit Root, was not a Heavenly Spiritual Root, nor did it belong to the Five Elements Spiritual Roots. It appeared more often.
One might appear every twenty or thirty years.
A Mutant Spirit Root was formed when two or three Five Elements Spiritual Roots combined, then underwent a mutation or transformation.
Under this world's rules, the wind-natured chakra in Naruto's original body—his Wind Spirit Root—had formed from a mutation of Wood and Fire Spirit Roots.
His Lightning Release Chakra, or Thunder Spirit Root, had formed from a mutation of Water and Earth Spirit Roots.
(As established in the original work.)
The differences in terminology caused by this world's rules had been corrected when he crossed over with the system.
Cultivators with Mutant Spirit Roots had no innate ability to bypass the bottleneck at the Core Formation Stage, but their cultivation speed could rival that of someone with a Heavenly Spiritual Root.
After all, a Mutant Spirit Root was still a single-attribute Spirit Root.
More importantly, Cultivators with Mutant Spirit Roots were generally formidable in battle if they practiced a Cultivation Technique suited to their attribute.
That made people with Mutant Spirit Roots highly welcome in the major immortal cultivation sects.
Unfortunately, after Naruto had gained the Six Paths Clones ability through the Eight-Tomoe Rinnegan,
he had split off four clones with single Wood, Water, Earth, and Fire Spirit Roots, leaving his original body with a Wind-Thunder Dual Mutant Spirit Root.
Naturally, two mutant attributes meant his cultivation speed was worse than it would be with just one.
So Naruto planned to find an opportunity to split off another clone with either a