Strange Rules: the Mutated World of Naruto

[Fan fan / Rules strange story / Slight fear / Tragedy] People in the ninja world only know chakra - it comes from the fruit of the sacred tree, introduced by Kaguya Otsutsuki, and passed down by the Sage of Six Paths. But chakra is not the "first level" rule of this world. Before the sacred tree took root and Kaguya came, there was already a set of "original rules" on this continent. They are not ninjutsu, nor blood inheritance limits, but laws of existence that are lower than the laws of nature - determining what can "exist" and in what form "exist". ''Original Rules'' have no will, no good or evil, like gravity, just "there". Mutation is not the arrival of monsters, nor is it the possession of evil spirits. It is closer to a kind of correction on the existential level - the "original rules" are re-validated, "correcting" back the parts forcibly covered by the chakra system. But the chakra system has been running for thousands of years, and all life depends on it for its existence. Life that has been "corrected" will become a form that should not exist.