video game character gone rogue

I haven't finished this game for ages already, but I guess I have the time to continue it with a different route. They seem to be aware of their surrounding, breaking the fourth wall at every opportunity they find. He's trying me to not to take this path. Genocide run, this game's path wherein you kill all of the monsters in Mt. Ebott possible.  I know he is aware of I took this route, I killed Toriel on my first encounter. I killed everyone I encountered in this run: his brother, his friends, his company. 'If you keep going the way you are now... you're gonna have a bad time.' He already warned me. They already recognised me as the first human.  They begged for me to spare their lives, but I didn't.

"i t' s  a  b e a u t i f u l  d a y  o u t s i d e . "
"b i r d s  a r e  s i n g i n g, f l o w e r s  a r e  b l o o m i n g. "
" o n  d a y s  l i k e  t h e s e, k i d  s  l i k e  y o u  s h o u l d  b e . . . "

It was too fast for me to catch up. His beams are everywhere.

"Heya, you've been busy huh?" He was facing me. He suddenly paused for a while. "So I've got a question for ya." I kept the silence to make him continue, he knew I was paying close attention. "Do you think even the worst person can change...? That everyone can be a good person if they just try?" he chuckled. "All right... Well here's a better question." I know that grin he makes, it's the usual grin you see from him everyday but this time the vibe in him changed. "Do you wanna have a bad time?"
I knew it. "because if you take another step forward... you are REALLY not going to like what happens next." I came this far for this run, I spared no one in the path. I didn't feel any mercy.

I took a step forward.

"Welp... Sorry, old lady." The game's about to start.

"this is why I never make promises."