While Billy kept leveling up Mental Armor, he also tried to come up with ways to learn the improved version of the current skill. At first, he thought that he could think of better ways to use Dream World. However, even in such a dimension that followed his rules, he couldn't find the answer he was looking for since it was based on his knowledge. At the same time, he couldn't make his friends or himself practice the limits of the armors there… for the same reason.