Obviously, that was just Abel's wishful thinking. He was busy now. There wasn't really a time to build a house until this was over.
After picking up Johnson's head, he inserted his power of Will into the stone metal monster that was lying on the ground. Since there was the essence of a dragon in his soul, he was able to kill the stone metal monster's remaining soul.
The stronger Abel became, the more control he had over the dragon's power that was inside of him. As little of it there was, it was powerful enough to kill many, many creatures with the slightest dose. It was the same for the stone metal monster. Now that its soul was eradicated, all that remained was a pile of useless metals.