It was unknown on how the Grimmson family could accomplish such odd feats of a Semblance, that is until now, thanks to a further in depth of the Grimm tissue that was collected from Obsidian, Willow, and Yomodo, the Grimm skin shows a type of Cell that is not known by science, to confirm a theory a scientist known as Dr Medicine, was granted access to The Sanctuary, where he studied Obsidian's motionless Grimm, and found matching cells, and then sent out to search for a non Grimmson made Grimm, successfully catching one, he studies it's unique cell tissue, and finds once again a match, and dubbed this unique cell group Nega Cells. 

Dr Medicine then asks for a slight experiments, Yomodo accepted the experiments, first using a chemical compound that only affects Nega Cells, making them glow green, he then asked Yomodo to try and shift her arm into a Beowolf arm, the results failed, she managed to turn her finger tips into claws before it backfired on her, where she then fell to the ground and started to complain that she was starving, which then opened up to a hypothesis. These Cells need a fuel in order to replicate Grimm in summoning and or appearance, after Yomodo ate a rather hearty lunch, she proved the hypothesis right, again, again, and again, it was however on the fourth time, that something bad started to happen, she was becoming rather moody and then feral, as black cracks started to form around her eyes and arms. Which once again opened a new theory, In order for a Grimmson to stay sane they need to feast constantly, in order that they don't become psychopathic grimm mutants, However once again samples from Grimmson Grimm are more different from Normal Grimm cells, which brings a conclusion that the Grimmson cells are replicated in some manner, Normal Grimm Cells are given the titles Nega Cell Tissue A, and Grimmson Replica of NCTA, is NCTB (Nega Cell Tissue B.) As for other Grimmson DNA, the rest is still unknown, like as to why the semblance transfers over to a Grimmson's married mate, why is it Grimm that activate this semblance when they touch a Grimmson, and yet how does it work?

Until next time, Dr Medicine will update you all later.