I recently came across Demon Sacred/Demon Seiten https://www.mangaupdates.com/series.html?id=1104. I just really want to know how it ends, it can be a summary or the raws I'm not picky. Honestly the
best character to me was the regressed sister, I just want to know whether she ever grows up

i know she stops regressing . Honestly even a simple yes or no would suffice if anyone could help me out.