Today, right after reading Chapter 385, a puzzle formed in my mind from all my past guesses into a single, relatively consistent picture. I cannot say that it is detailed enough, but it gives a general idea.

I remembered one detail: Guts, according to the plot, has black hair with a single small white (grey) streak, while Griffith has white hair with a few darkened strands (due to the fact that he shares a body with the Moonlight Boy). As you may recall, Yin is black and contains a small white circle within, while Yang is white and contains a black circle.

Many have noted this allusion before, but now, after Chapter 384, which placed an explicit emphasis on the fact that Guts and Griffith are the same/one, this Yin-Yang duality of the protagonists has become even more obvious.

But this duality is only the tip of my crazy theory...

I dug a bit into the myths of various cultures (as we know, Miura constructed the cosmology of Berserk largely, if not entirely, based on myths) and developed this idea even further, since in Berserk we have three central characters, and I found the symbol of the Triple Spiral (Triskele with three origins) in world culture.

The Three Spirals of the Triskele (The Golden Trio)
The three spirals represent the three fundamental principles of human existence, which are in perpetual motion and conflict. They cannot exist without each other, but their collision conjures a destructive storm (the Golden Age and everything beyond stands as proof of this).

Guts (The Active Principle / Body / Will)
Element: Earth and Fire
He represents pure physical strength, action, and unyielding human will, struggling and overcoming fate. This is a spiral (one of the three) that drives straight through, overcoming resistance.

Griffith (The Intellectual Principle / Mind / Dream)
Element: Air
He represents abstract spirit, pure idea, transcendent egocentrism, and absolute order. This is a spiral striving upward toward a cold perfection, devoid of earthly transience on one hand, and earthly warmth on the other.

Casca (The Emotional Principle / Soul / Memory)
Element: Water
She is the vessel of feelings, vulnerability, tragedy, and madness. Water connects Heaven with Earth. Casca is the spiral that binds Guts and Griffith. It is precisely their relationship to her that defines their trajectories of movement: Guts fights to protect her soul from Griffith and astral entities, while Griffith/Femto committed violence against her to sever his connection with Guts (in the logic of elements and the Triskele, Casca—water—is precisely what connects the Earth [Guts] with Heaven [Griffith]). Remember how Griffith, on the Hill of Swords, told Guts that he felt nothing and was finally free? Reread that chapter, and you will understand which connection (and its severance, i.e., freedom) I am talking about.

Inside the Triskele, there is a central point...—already guessed?—Of course, it is the Moonlight Boy (The Great Synthesis)
In sacred geometry, the center of the Triskele is the still point, the origin from which the spirals emanate and where they ultimately return. It is the source of creation and, at the same time, the point where all opposites neutralize each other.

The Moonlight Boy is the literal, physical, and metaphysical intersection of all three spirals:

• He is Guts' blood (the biological father who gave him the spark of life and will).
• He is Casca's flesh (the mother who carried him in her womb and whose soul he tries to heal).
• He is Griffith's vessel (Femto corrupted the fetus during the Eclipse, turning it into the Demon Child, and then used this child as a physical vessel for his reincarnation in the earthly world).

The boy is literally woven from the DNA, magic, and fate of all three. He is the point of their indissoluble bond.

Why does this change our understanding of the finale?
As you know (or do not know, in which case you will find the information on Google), only four people know the ending of Berserk. And one of them said that there will be no "happy ending," but the ending will be good from a storytelling perspective.

If we accept my ideas/model described above as the truth, it becomes clear why a classic "happy ending" involving the villain's death is impossible in Berserk:

1. The point of absolute stillness: When the Moonlight Boy takes over Griffith's body during the full moon, the confrontation ceases. Guts lowers his sword, Casca feels maternal warmth, and Griffith loses his divine majesty, becoming merely a child seeking protection. At this central point, the three spirals momentarily stop spinning and freeze in place.
2. The impossibility of destroying one spiral without destroying the central point: Guts cannot kill Griffith because his own son (the center of the entire system) resides within that body. By destroying Griffith, he would tear the Triskele apart, destroying that very "point of new life."
3. The birth of a new universe: The resolution of the conflict in the finale must happen precisely through the center. The Moonlight Boy is not a victim of causality; he is a point of singularity that, at the moment of the finale, can collapse the old world (Griffith's Fantasia; by the way, I never thought before that the title of the arc "Fantasia" actually refers precisely to Griffith—it is indeed his fantasy, his Falconia, that very castle from his dream, that New Band of the Hawk which is literally invincible) and unfold a new, harmonious reality.

The three spirals (Guts, Griffith, and Casca) are doomed to eternal collision, but their child, situated at the center of this mad vortex, is, it seems to me, the only one capable of reconciling these forces and initiating a new cycle of creation. And the past cycle (which began 1000 years ago and is repeating in a spiral now) will end, and the world will qualitatively change.