Soul Strengthening

Soul Strengthening (霊魂強化, Reikon Kyōka) is a phenomenon that occurs when a undergoes a metamorphosis in which its constitution and foundation are enhanced by some degree, causing it to become "evolved" in some sense of the phrase. More often than not, this suggests that a soul has reached a higher dimension than its previous state of being. It is an obscure field of research that has been notably studied by, who created the concept , as well as  and , who both pursued the possibility of  as a means of strengthening the soul of a.