The child made his choice, stepping back into the dungeon the very next day. He stated that losing his trait would make him 'not him' in some way, which Erryn could not understand, but was obviously important enough to the child for him to risk his life for it.

What was it that made someone themself? What was it that made Erryn 'Erryn'? She would have answered that it was the soul, and it wasn't as if she was swapping one out for another. Making small changes and rounding off alien corners didn't make it something different. Souls weren't static things anyway, always evolving over time. She hadn't done anything to him that had a larger effect than ageing would have. She certainly hadn't done anything that had a larger effect than falling into another world and being reborn with intact memories had.

He also asked what Erryn really wanted, which was getting a bit circular. Erryn wanted to know what he wanted. No matter, he was back in the dungeon now. A few more days and she would finally be able to get inside his head. The party he was with pushed him a lot harder than the previous day, leading to yet more gains. Combined with the trait evolution, it brought him even closer into line with the natives.

And that was another thing. He'd evolved two of his traits now, all on his own. The System rewarded him for it, but it was him making the decisions, growing his own soul. Why was that okay, but losing a different trait wasn't? No matter, not much longer now and she'd get her answers, and finally be able to understand.

The next day was even better, the party deciding to take him all the way to the bottom floor. That was far beyond his current ability, but they wanted to show him what the finish line looked like. How far he still had to go. Once at the bottom, the child could see straight through the perception block that hid the core room. Of course, the rule that the dungeon core must be accessible had long since been a thing of the past, but having a real passage helped keep the mana flowing. It wasn't as if there was any way for delvers to enter it.

Until now, that was. The child could pull others through with him, as long as they didn't look where they were going. Getting the child into the core room would let Erryn complete her work in one fell swoop. She didn't really want the others traipsing around in there, but there was no way the child would enter on his own, and she didn't want to spook him by just teleporting him. Not at this point, when she was so close. The party was too cautious to walk through a door they couldn't even see, so she had to force the issue by shutting off the teleporter.

Erryn was interested to see who was curious about what, one member of the party browsing the statues, which were purely decorative and had no value in Erryn's eyes. Three more looked at the core, which was only a low level one, but to these delvers would be an amazing find. They were welcome to inspect it while they could, but they wouldn't remember it; for her own safety, Erryn didn't allow her children knowledge of her largest weakness.

The last one was looking at the memorial along with the child. The child's gaze seemed to land on one name in particular. Erryn remembered it, one of a pair of catkin brothers, fallen on the eighth floor to a goblin assassin. The surviving brother had never re-entered the dungeon after that, and Erryn hadn't seen him again until she started to watch the child. He had turned out to be his next-door neighbour. A coincidence, perhaps, but only a small one. There were others in the same position, and the child just happened to be born next door to that one.

Having the three delvers poking around the core was interfering with her probing of the child, but Erryn still made good progress. She could see the surface of his mind now. He was... saddened by the name he was looking at? Why? It was someone who had died long before he was born. Neither knew the other.

An ancient memory stirred from the depths of Erryn's history. From a time when she was smaller, lesser. From a time when she, who could shed no tears, had nevertheless cried. That memorial existed still, no longer on the surface, but moved away from the elements into the protection of the great dungeon. Here lie a people that I never knew, yet I weep for their loss.

"Why would it write down their names in a room no-one can even enter?"

Wasn't that obvious? What were memorials normally for?

"To remember."

And yet she had so nearly forgotten... The child looked around in confusion, and Erryn realised that in her distraction she had unthinkingly spoken. And the child had heard her! She was almost there. Digging further into his mind, she saw an echo of hatred. Not sourced from the child, but from the surviving brother. Again, why? They chose to enter the dungeon. They knew the risks.

"Do you resent me? They made their choice, and they had their chance. What reason have they for regret?"

"I'm sorry, but I can't hear you."

A pity, but no matter. Erryn had what she needed. It was simply a matter of time. The next time he entered the dungeon, she'd have finished her adjustments.

"No matter. The next time you are here, my voice shall reach you."

Erryn ejected the party from the dungeon. Tomorrow they would step in once more, and by then she'd be ready.

Her expectations were dashed when the party that had been tasked with training the child decided to quit, and the child returned to his village. That was... vexing, given how close she was. All she needed was for him to step into the dungeon again, and she'd have been able to communicate properly. Now she would need to wait. Still, it wouldn't be long. Even if he never came back, a few more levels, a few more edges removed from his soul, and proximity to a core would no longer be needed.

Erryn watched the child in his village smithy, where he produced a little box with a line of bells, with mechanisms such that pulling a board through the box rang them. It seemed a bit pointless, but the child was talking excitedly about how you could replace the board with other things that would run for far longer, how it could be powered by springs to avoid someone needing to pull the board manually. The result would be something that would play music all on its own. It wasn't something Erryn had ever seen in this world before. Was it something from his old one? He took it with him back to the town, having gained even more skill levels in the process, and even another class level. It was enough. Erryn could read him now where he stood.

Erryn took in the child's memories of the other world and saw a completely alien landscape. Impossibly tall buildings pierced the skies, horseless carriages packed onto the roads between them. Birds of metal flew through the air. Devices for cooking, for preservation, for lighting, for communication. Some that seemed to serve no practical purpose but just produced moving images. They even had their own equivalent of the Akashic Library. The world was completely without mana, yet was full of things that ran off some sort of tamed lightning, which seemed to be a whole sort of magic of its own. It was a pity that the child hadn't been particularly well versed in how any of this stuff worked. Perhaps none of it would work here anyway. It was certainly a very different place; no wonder he had been so confused on his arrival here.

It was also a violent place. Not only had Peter's own death been a deliberate act, but even a supposedly peaceful city had streets you couldn't walk down if your skin was the wrong colour, or at the wrong time of night. The poorer parts of the world were left to starve while the rich engorged themselves. Without the healing powers of mana, people died to any number of conditions that would be trivially treatable here. Wars raged continuously, both within countries and between them. The larger empires wore a veneer of peace maintained by their capability of ending all life on the planet, but still attacked each other under the surface. Would the war between Jetosu and Soutso have gone differently had Jetosu known about the final weapon in advance? Conversely, that other world could so easily have gone the same way as this one. And yet despite being a place of such violence, teetering on the edge of their own destruction, they had achieved so much.

She looked into his memories of this world, and she saw that his first impressions of reincarnation, and even the System, had been coloured by fiction. That was amusing, if a little sad. Erryn had read little in the way of fiction, having developed something of a hostile attitude to it after her unfortunate initial smut exposure, and this only reaffirmed its demerits. Luckily he had grown, and started to see this world for what it was, rather than letting his old world colour it.

His memories snapped into clearer focus and Erryn realised that he had entered the dungeon. She took advantage, working more quickly. She didn't need to talk to him right now, she just wanted to finish reading him. But he was moving too fast; he was going to leave again too soon. She redirected a passageway on the third floor, getting him lost and buying herself more time to browse his mind. Eventually he reached the boss despite Erryn's redirection, and yet more skill levels came. Erryn took advantage, stripping the last vestiges of his resistance to soul magic. The System confirmed the completion of her plan as it removed the trait [Abnormal Soul]. She hid that fact from him, yet to have the conversation she had promised herself to have before exposing him to the Law.

Now he was completely open to her, no different from any native of this world, so Erryn looked into the last remaining corners of his thoughts. And Erryn knew what he meant when he said that losing that trait would make him someone else.