Meanwhile, in a parallel timeline:

Alphys called me today. It had been the first time in what felt like ages since I heard anything from the lizard. I had been most worried about him, so to get a call was quite uplifting, or at least it would've been had the news not been so dire.

I was already briefed of the situation at hand. A human had fallen into the Underground and began killing every monster on sight. Most of the death I could understand. Many monsters attacked the human on sight, and it was just defending itself. Even when not attacked initially, I can understand why the human already believed that all monsters were hostile. After all, were we monsters not also guilty of leveling the same judgment upon all humans?
Well, one monster wasn't. I just wished that I knew better at the time as well.

But this human...There was no way I could stop that thing, even with six human souls. My best hope was to offer it a way home so it would leave what remained of my people in peace. Besides, who knows what absorbing six human souls would have done to me? The children I killed in cold blood, who's to say that whatever resulted from the fusion of their souls with my own would not become an even greater threat to the monsters than the human? A "horrible beast with unfathomable power" doesn't sound like the proper solution to this scared child. They say this child is a demon. If that is true, then it's best to send it back to the humans. They would be far better at handling this thing than we monsters are.

So, in the end, I simply told Alphys to continue with the evacuation. I said I would do what was necessary when the time came.