He frantically looked around for his skeletal acquaintance, even back at his dusty shack of a house. The Underground seemed entirely empty to him, yet he knew that some monsters had escaped. Only some, yet he didn't know where to.
He heard faint music coming from the core, no doubt that conceited microwave. The dust flowing low above the ground hit him right in the face, before he dove into the dirt. He arose near the core, where some sort of powerful blast was heard before the music cut off abruptly.
Sighing, he dove back into the ground into… a very familiar place he had left behind.
Footsteps approached. He hid into the ground until they were directly above him, to which he popped out..
"Howdy, Chara! You made it home. Remember when we used to play here? Hee hee hee… Today's gonna be just as fun!"
They responded with nothing. They just kept walking and nearly ignored him. As they walked over him, he noticed that they were wearing the childhood locket that he remembered so dearly.
He popped back up in front of them, sensing their slight annoyance.
"I remember when I first woke up here. I was so scared… I couldn't feel my arms or legs! My entire body had turned into a… Well, you probably already know that, huh? I mean, with all the resets that have been occurring, obviously you've done this before. After all, you've gotten them to the surface a few times, and then you got bored. So you started experimenting. Toying with monsters' lives as you pleased. And every once in a while, something changes. But I bet you weren't expecting that fool of a skeleton to jump out, were you?"
A single tear dropped from their face, splashing on the ground into a million pieces. Just like the innocent monsters that had to die for no reason in particular.
"Shut up, Asriel." They said, clenching the knife's handle with white knuckles.
Those words struck him right in the heart. He shouldn't be surprised, really. They have, after all, done countless resets. But those words were something only Chara would say. Not this human.
He knew his sibling was in there, but he knew that he couldn't get in their way. After all, creatures like themselves wouldn't hesitate to kill each other if they got in the other's way.
With a sigh, he said: "Alright, Chara, do as you must."
He had never said such empty words in his life.