Originally they were not made of pure Antidermis energy. Originally they were completely biomechanical as any other being in the Matoran Universe. I think it was Chirox who came up with the idea of transforming their bodies into energy, wasn' it...? EDIT: They were actually always brought to life from Antidermis, I think, but they didn't become the beings of pure energy that we know before later. Here's a quote on the evolution into pure energy, from BS01: Originally biomechanical, the Makuta race eventually evolved to a state of pure energy, in which they no longer had to eat, sleep, breathe, or could feel pain. This evolution was first noticed by Bitil, and Chirox learned by examining a sample of Kojol's essence what had happened to them. Teridax ordered the Nynrah Ghosts to assist them by modifying their new armor. Soon after, the Makuta made a collective decision to shun their inner light, becoming true creatures of shadow. Due to the threat posed to their new armor by Toa of Iron and Magnetism, Makuta began monitoring Matoran populations of those elements, and employed several Iron and Magnetism Toa in their guardian Toa Hagah teams, in order to keep them in check." Perhaps it was actually a natural part of a Makuta's life cycle? Well what I'm saying is that since they're made of Antidermis, they can't have a default form besides pure Antidermis. This question means their default form before they were living suits of armor, and before they shapeshifted at all. What they were when they were first born. Well for that, we won't know, because the current suits of armor are designed to hold Antidermis, not organs and stuff. So if there was one, it's something we haven't seen before.