Papyrus tried to stop the genocide committed by the human by all means, but ultimately fails. Though, through unknown means, Papyrus gains possession of DETERMINATION. Because of this, Papyrus tried to kill the human and end the genocide and the RESETs once and for all, but yet again, he failed. The human SOUL was too strong for Papyrus. So he decided to sacrifice the other monsters (including his brother) to get himself more LV. He is walking to his house to sacrifice his brother, Sans.