Know think about this... ( ͡° ͜ʖ ͡°) What if they all share the same thoughts, and feelings (everything) like the “Misaka Network” from the anime; a certain scientific railgun. In general a huge hive mind in a way.
Meg has the best development on the franchise for long time. also Mari use the same sking of the typical background characters so is nice finally a fixed character to them
^If you want to think about it the right way you can see the Hell taker as a guy trying to build a harem only to find out hes now stuck roommating with a bunch of rowdy lesbians.
https://manganelo.link/manga/her-shim-cheong-manhwa/
Here's a website that I found after scrounging long and hard for it. I wish I had found it sooner cause I paid to read it chapter by chapter on this dumb app. Ugh. There's a lot of ads but it's worth it y'all, I swear.