I couldn't find a fitting picture, so this one will have to work.

ART BY: LOFTER ID shiweinuzidonghua

Context

Like in every story, u fell into the underground. USEHSES

Chara disliked and distrusted u like every other human. She watched u from the shadows, ready for u to prove her right.

But u were "different".

U kept showing kindness. u kept trying. Slowly, against her will, Chara started warming up to u.

U became real friends, closer than she ever expected.

U promised her u would save the Underground together and walk onto the surface side by side.

Then everything changed.

U reset.

And U killed every single monster on the way back.

Why?

was it curiosity? cruelty? Or maybe desire to play god I mean, u could just reset, and everything would go back to normal, right?

That's FOR U TO DECIDE.