Credit to Ekdoodlesphear for for the code!!! LORE DUMP IN NOTES AND CREDITS!!!! rlly like how this came out and have an idea for a Rad art in the future as well as a Rad Pap art
LORE. Papyrus's battle body is made of plastic as I headcannon he found it damaged in the Waterfall dump and fixed it up after washing it. So that is why it is melting when his soul becomes exposed to radiation due to the heat radiation emits. Due to it also being plastic it is now fused to his rib cage. When the core malfunctioned he was out on patrol with Sans(Rad) so he was exposed to the radiation but it was a smaller amount due to Snowden's distence from Hotland. He is trying his best to stay positive for his brothers sake but he does understand the gravity of the situation. He is loosing hope though as Alphys struggles to fix the core without proper materials. Not to mention there being few ways to prevent exposure other than not going outside. Pap is one of the last monsters to pass away from the radiation as in refrence to how in a genocide rout in undertale and the pressure in his skull leads to his head exploding and his body desolving into smoke. This is also when the Star San's find Rad and take him out of his AU. Papyrus is also fully blind due to his damaged and cracked eye sockets, when the cracks spread to the other eye that means the monster is close to death. That's all, I don't have much on Papyrus or the others yet cuz most of my foucus has been on Rad but I tired my best!!!