If one were to depict the life of the Spirit of Origin, Mio, with vivid colors, there is no doubt that her memories all revolve around Ryuya. This is absolutely certain.
The day she first met Ryuya.
Every day she spent living with Ryuya.
The day she parted from Ryuya.
Every day she longed for Ryuya.
Every day spent following Ryuya's requests, doing the things he asked her to experience.
And... the day she decided to make Ryuya a Star God like herself, forging his path to divinity.
"Ryu..."
The day Ryuya played hide-and-seek and left her was still vivid in her mind. Unable to imagine what would happen to her after being separated from Ryuya, Mio only knew she had to follow the instructions he left behind, experiencing each life event he wanted her to.
However, completely unable to comprehend human thinking, in Mio's heart, Ryuya's existence was irreplaceable. She absolutely... absolutely would not allow anyone to take him away.
Performing the life experiences Ryuya had assigned in a state of bewilderment, unable to truly immerse herself, Mio missed Ryuya more and more.
Her thoughts began to spiral, and she concluded that Ryuya had left because he wasn't strong enough.
In that case, all she needed to do was make Ryuya the strongest being!
Everything was for Ryuya. Everything was to make Ryuya the most radiant, shining existence in her memory. For the sake of these feelings, Mio fought alone, persisting for thirty long years.
Bestowing Sephira Crystals upon Nia, Yoshino, Kurumi, Miku, and other girls.
Serving as Murasame Reine in Ratatoskr, observing human reactions to Spirits.
Raising Mukuro, treating her as her own daughter, and so on.
In short, for Mio, everything in this world began with Ryuya and also ended with Ryuya.
Among all these things, besides the time spent with Ryuya, there was one other matter she paid attention to.
That was the girl known as the true First Spirit, Yamauchi Sawa.
Different from the ten Spirits in the original story, aside from adding Westcott as the Eleventh Spirit, Mio didn't pay much attention to Origami. Instead, she bestowed the Sephira Crystal of the First Angel, Metatron, upon Sawa.
To make Ryuya a Star God, Mio split her own power, creating individual Sephira Crystals, which are super-magical gems that turn humans into Spirits.
Even so, Sephira Crystals are immensely powerful artifacts, and humans could potentially collapse under their strain.
So Mio was very careful, meticulously searching for each suitable candidate. She didn't want failures or unnecessary deaths, as Ryuya disliked pointless sacrifice.
Fortunately, due to Mio's exceptional care, she managed, albeit stumbling along the way, to successfully create several Spirits. However, even so, an accident occurred.
"Yamauchi Sawa, you are strong. Very strong. But you are only the beginning, not the end."
The Inverse Side, a world Mio created at her birth. Within the Inverse Side existed countless human's malicious thoughts, grudges, negative emotions, etc. Mio didn't intentionally collect these, as they were the essence of evil that actively flowed into the Inverse Side.
Seemingly afraid to exist in reality, seemingly targeted by some will of the Earth itself, Mio knew it was because of Ryuya's presence.
The Earth King, the Humanity King, the Planet King, the Gaia King… protecting humanity, protecting this planet.
Therefore, humanity could progress, the planet's existence was sustained. Although many didn't understand the meaning of a King, fate favored humanity, favored the planet, and that was enough.
The consequence of the Earth King's existence was the disappearance of evils hostile to humanity.
These malicious energies, which should have dissipated from the world, entered the Inverse Side due to the birth of Spirits and the dimension's existence.
Capable of devouring a planet's worth of malice but choosing not to, Mio suddenly realized this wasn't just malice… it was a key.
A key to formally elevate Ryuya from a planetary-scale existence to a Star God.
Nurturing Sawa, Mio had Sawa devour this humanity's malice. Combining the Sephira Crystal with human evil, Yamauchi Sawa would become the ultimate Spirit, the final piece for Ryuya's ascension to Star God.
During this long process, Sawa evolved just as Mio had planned. She further devoured the collective malice of all humanity, which became her multiple personalities.
General, Instructor, Accountant, etc.… countless personalities... Although most were useless pseudo-personalities, some possessed considerable autonomy and superhuman combat power.
Of course, above all these personalities was the strongest one: Sawa's original self, the master personality codenamed White Queen.
"Mio, have I... finally become the Guardian of Justice?"
Confused about her own existence, not even knowing the meaning of her survival, only one thing remained and persisted in Sawa's heart.
That was to become the Guardian of Justice!
Yes, after absorbing the malice of so many deceased humans, she had witnessed the world's potential end. Insisting, stubbornly maintaining the identity of justice, her departure became Kurumi's final pain.
Asking Mio if the task she needed to do was complete, Sawa wanted to return to reality, to her parents, to her friends.
"Yamauchi Sawa, you are only one step away from becoming the Guardian of Justice."
The Inverse Form of a Spirit. Besides the First Angel, Metatron, Mio also gave Sawa Kurumi's Inverse Form, and informed her about Ryuya's identity as the Earth King, the true guardian of humanity.
The final thing Sawa needed to do was offer herself up.
To become a... sacrificed agent of justice.