I don't watch BnHA.>By no means was I implying it's the most important theme
What I meant to say is that it is unlikely to be a deliberate theme that the author consciously choose.>what is truly valuable is character, not power.
What of the husband whos wife was kidnapped by yakuza? Where they not righteous of the spirit? What of inuyashiki himself who despite his character and power still failed to save some people who were in front of him. importance of power can not be dismissed. after all inuyashiki is an old man who could not do anything without his new powers, it is implied that his life was wasted and he sees this power as his destiny, a thing that would give his life meaning. kind of like those people in Kaiji who "sleep away" their lives but in a more positive manner. No cop could stop hiro and ultimately his personal choice lead him to his end. despite his bad spirit the powerless could not stop him, not even with alternative forms of power (like social pressure with kids in the park or a romantic manipulation) His life was just starting out, after his mom died and he went to live with his dead his money problems would be gone, he could finish uni and maybe become more moral and proactive then inuyashiki. There is no way of knowing and given how things did turn out, power was key, so I don't think there was a moral there.