Design for devil z and it's thrall storm surge
While in the six clan's possession the transmetal driver was overused and fed dark energon, unable to fulfill its mission of "accelerating evolution" by creating life like it used to do when it was the emberstone, it turns towards the other facet of evolution, mutation and death
The mistress of flame could feel when connection between her and the emberstone was tainted, but she never could've imagined the true extent of it, the closer she got to her fallen angel, the more control it took over her
Devil z is a living space time distortion born from the allspark's original vessel becoming corrupted, the programming vector sigma implanted into the emberstone having been twisted into a kind of malevolent life force that guides the almost demonic energy being as it carries out a simple mission "accelerate evolution"
It's presence creates blisters and tumors in reality that we only evade the full effects of as the earth and the solar system move through space leaving the bruises behind to heal the best they can. But creating an unmistakable trail that may at some point in the future bring unwanted visitors straight to earth if devil z remains here for much longer
Devil z only passively alters space, its like breathing to it, to do anything more intensive it needs food and drink, it knaws on metal and flesh and drinks souls to create mutations attached to matter, atoms are duplicated, materials are transmuted, extra fingers, more fluids and in the end the mutant will die one way or the other
The six clan thought they had the devil under control but the moment they ran out of food to feed it, it swiftly abandoned them and returned to it's favorite puppet. Not physically at first. At first it whispered words into the mistress of flame's audio receptors, giving her visions of godhood, trying to delude her into taking control. To take the matrix from optimus prime and feed devil z the allspark so it could become all powerful (a to z see?) and when she refused, it had already fed on her free will and claimed her body as a vessel for itself.