It’s brutal, but some of the characters are portrayed innocently. I certainly thought of Elfen Lied from the description.
I can’t remember for sure, but i think they don’t really act as cutesy as OP describes? i remember everyone acting fairly mature, not really in that overly cute way…
the OP reminded me more of higurashi than anything else
I’m honestly not familiar with current day concepts of magi-girls. Particularly within some of the social groups on lemmy. It may just be my lack of exposure to anime in the last 15 years.