LORE: During a reset, the player decided to delete sans due to his hard boss fight, though, sans woke up in underswap, right before the human killed underswap!sans, US!Sans died but before he died he told sans to take over for him, which sans promised, sans then took US!sanses scarf and "battle body" and went into the house, where US!papyrus was, and US!Papyrus noticed something off but brushed it off as sans accidently tripped and cracked his eye a bit (he somehow survived due to the battle body giving him JUST enough defense to survive) and thats pretty much it
