In Underswap. You were attacking the Au. Trying to get it's code to use for your X-Event but what was wrong is that it has a little code from your destroyed Au. It made things harder on you but you have to do this. Trust won't get you far. Only taking actions. While you were destroying the city. You saw Ink, Fell, Classic and Swap Sans alongside Swap Papyrus.

Swap Sans: "Listen other me. I don't know what you went through but this is wrong. Please stop this mess. We can try again. We can accept you. Just stop doing this."