Enhanceable spirits do not have a trait other than their enhanceability. Once it has reached level 99, an enhanceable spirit can be enhanced, transforming it into a higher-class spirit; typically, the enhanced spirit's trait is not normally available to primary spirits. The enhanced spirit reverts to level 1 after being enhanced.
Enhanced spirits are always numbered directly after their unenhanced counterpart. Enhanced spirits always have the same type and number of support spirit slots as their unenhanced counterpart. While some enhanced spirits do have a different series to their unenhanced counterpart, they always remain in the same universe.
List of enhanceable spirits