It would be so convenient to say I didn't do anything wrong! It was all Chara's fault! I never wanted to destroy everything! Wel, while that las part is true, I am no innocent. Chara would have never awoken if I had not hurt anyone. At first it was self defense, I had no idea what any of these monsters were capable of. For god's sake I was almost killed by a flower. Then I realized that I became stronger when I won. I thought that, just a little more and I would be strong enough to survive down here. With out really thinking about the long term consequences I started fighting monsters that couldn't possibly be threatening.
That is when I started hearing them. Encouraging me to continue fighting even ones that didn't even want to fight me, like that whimsum, who I could have sent away crying just by raising my hand. I never wanted to hurt Toriel, but by then I had lost control. I looked in the mirror and Chara was all I saw. They did not care for the compassion Toriel had showed them, the second she stood in their way they cut her down. And then Doggo, Lesser Dog, Greater Dog, Dogamy and Dogressa, Papyrus, Undyne, Muffet, Mettaton, Sans, everyone, everything. Maybe, had I resisted more, I would have been able to take back control before they killed everyone. But I was terrified of being alone in a world where everyone saw you as a homicidal maniac. So I just sat back and watched numbly as the underground was filled with dust.
When Chara asked if I wanted to erase everything, I said no. But it was too late to take back control and they erased everything. I stared out into the abyss that now replaced the world, with so many regrets. I tried to reload, over and over again, but Chara's determination was overriding mine. they laughed at me. They mocked me. They chided me saying that I would have to live with the consequences for my actions... unless... I sold my soul to them. Then they would reset for me. Bring back everyone. Allow me to try again. I agreed without hesitation.
This time I made sure to stay in control. I did not risk so much as tapping a single monster. It was hard, showing mercy to people who were trying to kill you, but I would make Toriel proud.