The Third Herrscher Core, like the Second Herrscher Core, fused with Mei's Stigmata, becoming the Stigmata Consciousness of Mei's Stigmata Space.
But the Herrscher of Thunder was different from Sirin. The Herrscher of Thunder was a child born from Mei's memories.
After being persuaded by Kiana's talk-no-jutsu and knocked sensible by a baseball bat, and then having her hand grabbed by Kiana on the rooftop, falling in love at first sight, the Herrscher of Thunder returned the body to Mei and entered the Stigmata Space for the first time in a true sense, returning there to wait for the day Mei would come crying and begging for her help.
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(Mei, holding a Homu doll, kneels on the ground in despair, crying and shouting: "Help me, Herrscher of Thunder."
Herrscher of Thunder: I'm fucking coming! Whoever made Mei cry, I'll never let them go! Whoa, Kiana, Herrscher of Finality...
Herrscher of Finality Kiana: Grabs the Herrscher of Thunder by the neck, *snap*.)
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However, when the Herrscher of Thunder returned to her Stigmata and entered the Stigmata Space...
She discovered that she was not the creator of this space, nor its first master.
The creator of this space was Mei's mother, Raiden Kikkaka, who had passed this Stigmata down to Mei...
The Stigmata Space looked like Mei's home precisely because it was built from the heart of Mei's mother.
Because for Mei's mother, this small home was her entire world.
But the Herrscher of Thunder found no trace of Mei's mother in this home. Because Mei's mother was just an ordinary person, and her Stigmata only began to awaken when she gave birth and passed it to Mei...
She left everything to her child, and this Stigmata Space was no different. Before she died, she had a glimpse of this space, and this home within the Stigmata Space was her last gift to Mei.
There was no replacement or struggle for the role of the Stigmata's engraver. Upon entering, the Herrscher of Thunder directly inherited all control over the Stigmata Space.
Similarly, as the Herrscher of Thunder looked through the records of major and minor events in the Stigmata Space, she also saw everything Mei's mother had sacrificed.
The newborn Herrscher of Thunder did not understand what love was, but just as she fell in love with Kiana after being saved by her on the rooftop, she wanted to save the woman named Mom who had given everything for Mei.
The Herrscher of Thunder was not a normal person. She was born from Mei's desire to destroy the world, so naturally, she didn't know or care about human moral concepts.
She only knew that she didn't want her to die.
The Stigmata Space in Honkai Gakuen 2 was created by "*****" inducing predecessors to break the gap between soul and matter. Just as people killed by the Honkai never truly die, the souls of those killed by a Stigmata wielder would also be imprisoned within the Stigmata Space.
The Herrscher of Thunder spent a great deal of effort exploring the Stigmata Space, but found nothing.
Until one time, she accidentally met someone who looked a lot like Kiana.
That Kiana looked very sad, but the Herrscher of Thunder didn't know how to comfort her, although she probably didn't need comforting...
As if she knew what she was looking for and wanted to do, she waved her hand and sent her to an unknown place.
There, the Herrscher of Thunder met another familiar stranger. Someone who looked a lot like her, but was completely different.
She said she was the "Scrivener," and then told the Herrscher of Thunder that if she wanted something, she had to trade something for it.
The Herrscher of Thunder wanted to find Raiden Kikkaka's soul, so she chose to trade her own soul...
The Scrivener took a part of the Herrscher of Thunder's soul and gave her Raiden Kikkaka's soul in return.
Having lost most of her soul, the Herrscher of Thunder's form began to shrink continuously, regressing to the appearance of a five or six-year-old.
But she got what she needed; she found her mother's soul.
However, Raiden Kikkaka was just an ordinary person. Decades in the real world had been tens of thousands, even hundreds of millions of years in the Stigmata Space.
Her soul had lost all its memories, leaving only a pure essence.
The Herrscher of Thunder thought she had just forgotten, so she would make her remember!
Thus, within the Stigmata Space, using its unique ability to record everything from the first-person perspective of the Stigmata wielder, she had Mei's mother relive her entire life.
And with that, the Herrscher of Thunder resurrected Mei's mother.
The only drawback was... Mei's mother only had memories up until her death, with no memories of what happened after.
And because of this memory gap, Mei's mother directly treated the five or six-year-old Herrscher of Thunder as her own daughter.
The Herrscher of Thunder went from initial reluctance to later being completely obedient, becoming Mei's mother's daughter!
But in the end, the Herrscher of Thunder still told Mei's mother about herself, about Mei, and about this Stigmata Space.
Having died once already, Mei's mother accepted it all with great composure.
Mei was still alive, Ryoma was still alive, and now she was alive too. Although she had missed Mei's childhood, she could still witness the growth of her new daughter, the Herrscher of Thunder.
So, what was there not to accept?
"And so, Mom and I have been living happily here ever since!"
The Herrscher of Thunder stood on the chair with her hands on her hips, looking proud and happy.
The floor was littered with used tissues; Mei had cried through several packs, nearly drying out her tear ducts.
She hugged the Herrscher of Thunder, feeling moved and happy, endlessly thanking her for everything she had done.
"Thank you... thank you... This is wonderful, truly wonderful... Thank you for saving Mom..."
"It's nothing special, this isn't really a resurrection... She can only exist in the Stigmata Space, and unlike me, she can't watch your life or browse the Stigmata Space. It's like a criminal who committed a great crime and was locked up, confined to this house, unable to even open the door and leave..."
The Herrscher of Thunder sighed helplessly, then her eyes flashed with lightning as she looked at Raiden Mei seriously.
"I know why you came, and I know what you need right now. I can give you my power, give you everything, but I have only one request..."
"What is it?"
"When you've settled things and resolved the crisis... separate Mom from the Stigmata Space, let her live a true life..."
"I will. I definitely will."
"Also, you must protect Kiana. Don't let her end up like that other one, so sad..."
"?"
Mei blinked in confusion, looking at the Herrscher of Thunder, puzzled. *That other one? Is something going to happen to Kiana?*
But the Herrscher of Thunder didn't say more, because she didn't know why that Kiana was sad either.
"Raiden Mei, take care of yourself. My soul is damaged, so after I give you my power, I can only watch you from here in the future...
So, do your best! You must defeat the Honkai!"
"Mhm! We definitely will!"