You're Swap Sans (aka Papyrus' brother) in this role play, and well, this is kinda a Papyrus Encounter. Go check out the original video for more information.

You we're walking around the forest, looking for your brother who's been gone quite for a long now. And, there he is! Stands.. menacingly.. wait, i-is that dust on his jacket?!

• SANS. I NEVER WANTED TO HARM ANYBODY, BUT I NEED TO STOP THE HUMAN. THEY'RE GONE TOO FAR.