there are 3 songs the last one is the best. story: after death, as a ghost, sans had only one target... frisk. he knew he couldn"t kill her if he was a ghost. sans made a shadow, containing all different types of sans. surely this will get frisk, he thought. but shadows couldn't hurt anyone, either. then, he realized that the shadow needed dark energy to come alive and kill, and he realized that he must sacrifice himself. he gave away his dark energy, dying completely. but a wisp of him went inside the shadow. the shadow was alive and had one mission, kill frisk. through all this turmoil, nobody noticed that nightmare sans was still alive and well. he wasn't a ghost, or in the shadow. he was a breathing, living skeleton. when the transformation was happening, nightmare sans took a bit of the dark energy in the shadow. he wondered what dark energy plus shadow could do to someone alive. he found out. he absorbed the shadow energy, but corrupting himself in the process. he didn't target just frisk. he targeted every other living being. the streets were filled with blood. blood from humans, from animals, from skeletons. when he was done, there were no other creatures with flesh in their bodies. nightmare sans turned them into a zombie army. nightmare sans wasn't nightmare sans anymore. he was a corrupted shadow. he was corrupted shadow sans. CS Sans forgot one thing. ultra dark sans... to be continued.
corrupted shadow sans: https://scratch.mit.edu/projects/328884569
