First of all Harting is NOT a Sans OC just so you know! ;) Basically There is AT Papyrus, Sans and Harting in AtmosphereTale. Here kinda a backstory of Harting. So Harting was born with Half a soul, so his mother gave him half of hers so he would live. Humans from below Save-point City killed her and her soul, both halfs, broke. As you know dead charcaters are usally in the save screen, but instead Harting got there since half of his Mothers soul broke, so yeah. Basically you fight him once an Unknown Error occurs and hes kinda like the last resort in the code, but he is the main antagonist of the stroy, so yeet.