"Let the world… forget you entirely…"
Nahida's eyes went wide. She stared at Buer as though the words had struck something physical, and when she found her voice, it came out unsteady.
"How , how can that be possible? No. I can't. I won't do it."
She tried to pull her hands back. Buer held them.
The gentleness that had characterised every expression Buer had worn since she appeared did not waver, but beneath it was something that did not yield , something decided, long ago, without drama.
"Nahida. I was born of Irminsul, and I will return to Irminsul. This is my purpose. It is my fate."
"In that sense, I was never a truly great god , not in the way you will be. Because for me, Irminsul always came first. Before Sumeru's people. Before anything."
"But that is not your burden. That chain ends with me."
"After this, you can simply be the God of Dendro , without conditions, without limitations. You can lead your people toward something good. You can live the future that was always meant for you."
"You will surpass me. I am certain of it."
"I cannot walk with Sumeru any further than this. I cannot stay to watch you grow into everything I know you will become."
She reached up and touched Nahida's face, her fingers light.
"But I can still give you one last thing before I go."
"Nahida, I will lay the foundation for your greatness."
"Let the world forget me entirely , and in doing so, save Irminsul. Save Teyvat. Save the people of Sumeru."
"This is your purpose, Nahida. And it is my ending."
"Let the world forget me, and then , we will become one, completely."
"There will be no Greater Lord Rukkhadevata in this world. In the end, at the very end, there will only be the first Archon , Lesser Lord Kusanali, Nahida."
"This is what is best for you. For Irminsul. For Sumeru."
She drew Nahida close, holding her the way a mother holds a child who has not yet learned that some goodbyes are final.
"Don't grieve. You won't remember me , but forgetting is not the same as parting. You are the continuation of my life."
"Sleep, and tomorrow will still be bright."
Nahida was no longer trying to speak in complete sentences. The tears had taken over, and her small hands had locked around Buer with the grip of someone refusing to let the tide take something away.
"I don't want , I don't want to forget you."
"I won't let the world forget you."
"We only just found each other. You have done so many things , so many great things , and you deserve, "
"You deserve better than this ending."
"I refuse this ending!"
The others had understood, by now, exactly what Buer intended.
She had known, for as long as she had known anything, that her own existence was the source of Irminsul's contamination. As long as her memory persisted , as long as any trace of her remained woven into the World Tree , the Forbidden Knowledge that had taken root in her would remain woven in as well. There was no separating them.
So she had created Nahida.
She had brought this to a moment where Nahida could, with her own hands, delete her predecessor from Irminsul's record entirely. A clean severance. The Forbidden Knowledge, bound to her memory, would go with her.
It was the sacrifice of everything , not just life, but the record of having lived. The most complete erasure possible.
And she had done it alone, without asking permission, without allowing anyone else to carry the weight of knowing until it was already decided.
Ningguang and the others stood in a silence that had no easy words inside it. The quality of what they were looking at was the kind of thing that did not invite speech.
Makoto pressed her lips together, then turned and looked at the Cryo Archon for a moment. Both of them understood, in the way of gods who had existed long enough to know what removing something from Irminsul actually meant. They had seen it done. They understood the mechanics.
"If you are erased from Irminsul," Makoto said carefully, her voice carrying the particular steadiness of someone measuring every word because the alternative is breaking, "then you are gone from every memory. Not simply unremembered , never remembered. No trace. No impression."
"From that point forward, Teyvat will have no record of a Greater Lord Rukkhadevata named Buer."
"Everyone who ever knew you will lose that knowing."
"The world will have forgotten you from the very beginning."
"Was it worth it?" Makoto asked. Not an accusation. An honest question, from someone who understood the cost of impossible choices because she had made enough of them.
Buer had already known Makoto was alive. The information had been in Irminsul, and Irminsul had no secrets from her. She looked at Makoto without surprise, only recognition, and the warmth in her expression deepened slightly.
"One life exchanged for a world that continues intact." She did not hesitate. "Yes. Entirely worth it."
"Besides , Nahida is my continuation. I have not disappeared. The world will not remember me, but I will remain in Ryen's memory and in Lumine's. That is enough."
She turned her gaze to Ryen, and something in the angle of it was almost gentle amusement.
"As Ryen once said , as long as one person still carries the memory of you, you have not truly died."
Makoto breathed in deeply. She bent at the waist, a bow that carried the full weight of what she meant by it.
"Buer." She straightened. "Thank you."
"Ryen!" Hu Tao grabbed his arm, pulling him around, urgent in the way she became when she had decided something mattered. "Think of something! You have to think of something!"
"She is extraordinary and she is brave and she has already done too much , you cannot let everyone forget her! You must have a way! Resurrection totem, milk, Totem of Undying , something, anything, just think, "
Ryen had not spoken.
Buer turned toward Hu Tao, her voice gentle.
"Please don't make this harder for him than it needs to be, Hu Tao."
"I understand, genuinely , the Resurrection Totem could restore me. But the milk, and the Totem of Undying, and what they can accomplish , I have seen their properties in Irminsul's memory."
"They are remarkable. They are powerful. But they cannot resolve Forbidden Knowledge."
"Forbidden Knowledge is not a curse. It is not a disease. It is a presence , it has embedded itself into the structure of my existence the way a splinter embeds itself into bone, and it goes all the way down. As long as I remember it, it persists. As long as it persists in me, it persists in Irminsul."
"Milk and totems address afflictions. This is not an affliction. This cannot be solved that way."
The light in every pair of eyes in the room had dimmed.
"Ryen." Ganyu's voice was very quiet. She was looking at Nahida , at the tears still running down Nahida's face, at the grip she had not released. "Is there anything else?"
"If Nahida has to erase her with her own hands , even if she forgets afterward , she will carry this. Something in her will carry it, even without the memory. She will spend her whole life in a pain she cannot name."
Yae Miko leaned close to his ear, her voice low enough that only he could hear it.
"You always have something. Don't you, my Lord of All Worlds?"
A pause.
"Think about it differently. Buer can't exist in Teyvat anymore , her existence here is what's killing Irminsul. Fine. Then she exists somewhere else."
"Your world is completely sealed off from Teyvat. If she lives there , permanently, without returning , the connection between her and Irminsul would be severed. The Forbidden Knowledge loses its anchor."
"And besides." A hint of something practical, and not entirely selfless, in Yae Miko's tone. "Do you really want to lose one of a pair of twins you haven't even properly met yet?"
Ryen looked at Buer and Nahida.
The two of them, indistinguishable in face and feature, holding each other in the pink-lit quiet of this space.
Something inside him settled with the particular decisiveness of someone who has stopped calculating and started deciding.
He nodded , once, immediately, without qualification.
"There's a way. I'll find one whether there is or not."
Buer blinked, startled out of her composure.
"Ryen , you want to… restore me? But my existence is the most terminal illness Irminsul has. I must disappear. That is the only, "
"Then disappear from Teyvat."
He said it cleanly, without ceremony.
"Nahida has only just found you. I am not going to let Nahida delete you with her own hands and spend the rest of her life carrying grief she cannot explain."
"Your existence is rooted in Teyvat, which is why the Forbidden Knowledge is rooted there too. Then take your existence somewhere else. Come to my world. My world has no connection to Teyvat , they are completely separate systems. Whatever the Forbidden Knowledge is, it cannot enter Teyvat through a door that doesn't exist."
"And your contamination , once you're there, I have more than enough resources. Eventually, we will find a way to eliminate it entirely."
"This solves everything. Does it not?"
Buer was quiet for a moment. She was thinking , actually thinking, not performing consideration , and something careful and guarded was beginning, very slowly, to open in her expression.
If she were honest: she did not want to cease to exist. She wanted to see Nahida's future. She had been willing to give those things up because there had been no other option she could find, and she had calculated every possibility she had access to and found none.
She had not calculated Ryen.
The MC World. An existence completely sealed from Teyvat's laws. A World Master whose jurisdiction extended over every rule that operated within it. If she were simply no longer part of Teyvat , if the link were cut by distance and dimensional separation rather than by deletion , then perhaps the Forbidden Knowledge, which had always moved through that link, would find no path back.
The probability of success, when she ran it properly: high. Considerably high.
But before she could hold the feeling for long, something else surfaced, and her expression fell again.
She looked back at Irminsul , at the image she had shown them, the real one, the tree as it actually was: black-wrapped, root-deep with contamination, barely holding the shape of something that had once been light.
"Your intention is kind, and I receive it." Her voice was soft, and sorry. "But I cannot accept it."
She gestured toward the tree.
"Moving me out of Teyvat would prevent new contamination from reaching Irminsul through me. But the contamination already inside Irminsul , five hundred years of it, embedded in the root structure , will not leave simply because I do. The damage that has already been done is sufficient to destroy the World Tree on its own timeline. I would be gone and Irminsul would still be dying."
"The only path I have found is this: I gather every thread of Forbidden Knowledge that exists within me, consolidate it, bind it to myself completely , and then I am deleted. The Forbidden Knowledge is deleted with me."
"That is the only clean ending."
The room, which had briefly lifted, settled back down.
Ryen's brow drew in slightly. He was quiet for a long moment, thinking with the particular quality of attention he brought to problems that required something to be cut rather than untied.
"You said you can concentrate the Forbidden Knowledge , pull it together, draw it into one place?"
"Yes," Buer said. "But even so, Forbidden Knowledge cannot be affected by external force. That's precisely why the only viable solution is, "
He raised a hand. She stopped.
He reached into the air beside him and drew out a sword.
It did not make an entrance. It simply appeared in his grip, unremarkable in the way that things are unremarkable when they have always been exactly where they belong. But the moment it was present in this space, the space knew about it.
The Sword of Cosmic Dominion.
He turned it once in his hand, unhurried, and looked at Buer with something that was not quite a smile and was not quite a challenge but was somewhere between the two.
"Everything that exists in form."
"Living things. Dead things."
"Gas. Solid. Liquid. Light."
"If it has a form , if it has any form at all , there is nothing this blade cannot sever."
He met her eyes.
"Cannot be affected by external force? That is a question of scale. Apply enough force, and it stops being a question. Enough force, and you could reach the base of the Imaginary Tree and rip it out of the ground with your bare hands."
"And as it happens, "
He tilted the sword slightly, and the edge caught the space's pink light and held it.
"Under the Sword of Cosmic Dominion, existence is the only criterion for destruction."
"Laws. Concepts."
A beat.
"Those too."