You stare at the grey humanoid canvas in front of you, still traumatized by what had just happened. Your family, friends, co-workers, the entirety of the human race, gone. Just because you wanted some strange lady's golden ring. "Ah," the aforementioned strange lady says in your mind. "So you're feeling guilty about destroying your whole species? You can change everything back, you know. Have all the canvases return to their former human selves, and you can watch as they go back to their dull business..."
Her words fail to convince you, however. You had decided to look at this situation in a different way: You were now basically a god! You can mold the world into your own playground, where you can explore your deepest desires with a potentially infinite amount of individuals who could come from the units.
You refocus your attention back to the unit in front of you, eternally standing in place unless you give it an order. A transformation would be a good place to start for this unit, you think, so you brainstorm various generic fantasy races. Eventually you decide on a centaur, not only because you could do a lot of interesting things with it, but it being half-human is symbolic. At least it is to you.
You give out an order to the canvas. "Unit, transform into a beautiful centaur, more brilliant than any human."
The unit responds. "Accepting instruction, Master. Beginning transformation."
You can only watch in awe as the unit's formerly grey skin becomes brown and pink. It gains a butt, which then begins expanding, and then that butt gains its own legs, which turn into horse legs. The canvas' face goes from androgynous to extremely feminine, and this makes you suspect that it is becoming a centauress. A pair of enormous boobs emerges from its chest, which confirms your suspicion. Perhaps this unit was female before the... incident.
Before long, the transformation is complete, and you stare at your handiwork. A giant, imposing centauress stands before you. She must be at least seven feet tall. Her brown hair falls to her waist, and partially covers her busty rack. Her horse side isn't slacking either; it has powerful looking horse legs with massive thighs, a giant belly that looks like it could digest anything, and a bubble butt that just from looking from the side you can tell is amazing.