The Exotic Creator took Eggsicutioner back to an Inkperial laboratory, much more advanced than the one he was built in. Exotic Creator kept him there for a while, where he was monitored and tested, leading to little results and the death of a few scientists because they were perceived as obstacles to the robot. Despite this, Exotic Creator kept him out of interest, and a loose idea.
One day, after Omeletta's death when she attempted to attack an Inkperial base, and Eggyhead's family were with the Yukuna family, the Exotic Creator visited a special site of ancient Egg ruins. He found something that intrigued him in the murals on the wall.
There was a depiction of an angelic being in the center of a wall. As he followed throughout the ruins, he came to realize something that gave him an idea. The angel depicted was none other than Eggyhead, or rather the being inside him that gave him his power. He figured if this power was as strong as the murals described it, harnessing it could be a great step towards the new world EC envisioned. He did not know how he would do this however, but eventually, his brainstorming bore fruit.
He had a template to build off of right in the middle of his lab. And so he returned, and began to create a machine in the image of the angel he saw at the ruins.