The renderings looks good except for the mother, her body seems really disproportioned. I'm not talking about the giant tits, but her whole body is actually weird, her head is really small in some renderings compared to the rest of the body. I don't think the developer is Eromersive (as many suggested) because EM created perfect balanced bodies. In The Synthetic some bodies are really badly executed. The MC has got the skin of a 80 years old, he looks like a zombie, it's horrible.
Since Eromersive's and Carbon's VNs are so similar in many other ways, it's possible that Carbon simply adopted Eromersive's posing techniques or that Eromersive actually taught him how to do it. However, I don't think they are the same person. One more example? Even after two years of inactivity, Eromersive continues to make more money on Subscribestar than Carbon earns at the moment. Therefore, developing Demon Boy further would be more profitable than creating The Synthetic.