Sans files got messed up being non repairable if he is able to defeat the player, he traps them in the game to become the new Sans, making them relive their own worst resets forever While he escapes from the game and goes on to torture other players and make them feel the same pain he did. While he enjoys all the suffering of them Sometimes he even joins in on the fun which can be gory after a long of times of doing drives him insane and thus wanting to attacks and takes down anything on his way