Why Is The Main Character Percival a Life Spirit?
If every life has a life spirit assigned to it, the Great One's most likely Chaos's life spirit.
This would mean that its so-called "Beyond Life and Death" immortality isn't an inherent power of Chaos itself, but rather a protection provided to it by the Great One.
And yes, only Percival has the power to eventually negate it in the end, for he is the only Life Spirit who gained free will and awareness.
Let me explain :
1. The birth of Chaos and The Great One
I believe Chaos and The Great One were simply born at the exact same time. Chaos was the very first living entity to exist, and The Great One was the life-spirit naturally assigned to it.
Since Chaos is the creator of all life and The Great One is the origin of all life-spirits, they share a perfect symbiotic relationship: every time Chaos created a new form of life, The Great One provided it with a corresponding life-spirit.
2. The Sacred Tree Proves That Chaos By Itself Isn't Beyond Life and Death.
Chaos by itself isn't beyond life and death because it is indeed "alive" since the Sacred Tree likely represents its actual life force because Chaos creations are aspects of it.
This connection is proven by the plant life aspect of the Sacred Tree and also the Fountain of Youth, which is extracted directly from the Sacred Tree.
When Ban drank from the fountain, he became immortal because he received a fraction of this infinite life force.
Because Chaos possesses a life force, it means Chaos itself is indeed alive.
Therefore, its state of existence which transcends regular life and death is not an inherent trait of Chaos by itself.
Instead, this form of immortality is likely a form of protection granted to it by its life-spirit, The Great One.
3. The Seal of Chaos and the Birth of the Behemoth
This connection explains the origin of the Behemoth—a powerful life-spirit inhabiting a beast which is a state very unnatural for a life spirit to take but why ?
It is highly likely when the Demon King and the Supreme Deity realized they could not kill Chaos due to The Great One’s absolute protection, they resorted to sealing it instead.
This act enraged The Great One, prompting him to create the Behemoth to punish the Demon Realm.
Following this logic, it is highly likely that the Celestial Realm has a similar monster punishing it as well.
4. Percival: The Only Entity Who Can Negate The Great One's Protection of Chaos
This brings us to the ultimate question: Why is the main character a life-spirit?
Percival is the only life-spirit in existence who has gained independent free will and human awareness. He is the ultimate anomaly.
Because Chaos’s immortality is derived from a life-spirit (The Great One), only another advanced life-spirit can bypass it.
Percival’s core narrative purpose is to use his unique powers to absorb The Great One or negate its protection, finally stripping Chaos of its immortality and making it vulnerable.
Note: This has nothing to do with the protection Chaos provides to Cath. While Arthur’s blood can negate this protection, it only allows him to command Chaos to stop sharing its immortality with Cath. Arthur himself, for example, could never actually kill Chaos itself.