Something I read in one of the fan wikis was that Andrealphus is jealous of Stolas because Stolas is Lucifer's top prophet, but I can't find a source for that. Has that actually been said in canon? It would explain why his rather extreme assholery is tolerated.
Also re Stella, if you look at it from her perspective she has every reason to hate Stolas's guts. Her main concern is keeping up appearances and Stolas does nothing but constantly be a public disgrace and humiliate her at every opportunity. She may have hated him on sight but she certainly wasn't trying to outright murder him until fairly recently.
Consider that the one thing she cares about most is reputation and social standing, and Stolas couldn't treat that with more contempt.
And it's not like he only treats Stella this way. He's been completely inconsiderate to Octavia too, the one character (other than Blitz) he actually cares about.
Seriously, Stolas is a narcissistic asshole. A charming, charismatic narcissistic asshole, but an asshole nonetheless.
Even jacking her cuntery up to 11 to make her the obvious designated villain still doesn't erase the fact she has every reason to hate his guts, even if the whole arranged marriage thing wasn't really his fault. He basically broke the royal social contract that in one of these arranged marriages, you maintain appearances while keeping your affairs discreet.
I think she would have hated him considerably less had he not insisted on being an utter public disgrace to the point his name is a joke, something he doesn't care about but causes her considerable tumult.
tl;dr Stolas is a lolcow.
