Papyrus is the secret boss of ch.6 and he is going to rock your shit. You remember the switch between frail undertale Gerson and Deltarune Gerson? Well remember that Flowey needed 4 vines to restrain Papyrus, and only 2 for everyone else including Sans; Papyrus never got to use his 'ultimate attack'; and whatever occurs in Deltarune is going to make him hate humans with a passion by the time he swaps dimensions.