both are kind of terrible and genuinely fucked up people!!!
meenah is…a lot to process. she’s )(IC sans years of manipulation and becoming a bloodthirsty quasi immortal empress with the galaxy at her clawtips. she could become a killer queen, but in her reality, soft and sweet beforus, she decided to say fuck it, ignore responsibility, and fuck off to the moon. would she have overthrown feferi if she tried? absolutely. but that’s fodder–meenah never grew up, never grew past her own selfishness (or should i say shellfishness LOL), and never moved forward. eons spent in isolation didn’t help, either, and she’s not exactly tragic or comedic? she’s just a fucking weirdo with fish puns and genocidal tendencies that she can’t exactly act on. all bark and no bite.
aranea on the other hand is cool, composed, articulate. unlike meenah, who’s in your face with her bluntness (and like. general ability to never sugarcoat things that actually need a gentle touch), she tries to be your friend, to get on your side. she wants to be liked, because fond memories are better than no memories at all. and yet! that quest for relevance is sourced in anything but genuine kindness.
aranea, in another life, becomes a cold and calculating saboteur. she sails the seas, ransacks the innocent, and rapes someone as an act of foreplay with her boyfriend. she is hunted down, she mindcontrols an entire gallery of people to kill someone (and presumably themselves, to eschew witness accounts). she starts a revolution out of boredom and because she wants some dick. like…there’s nothing really positive about marquise spinneret mindfang. she does everything for personal gain and has no regard for other’s lives. she writes about her conquests, because she wants to be remembered. and she is, by a little girl with no other adult to turn to.
tl;dr: meenah is chaotic but a dumbass! aranea is calculated chaos!