Isis asking real questions. Thinking a lot about how these two's relationship work. Sev being the anxious aggressive mess he is he would be constantly insulting Isis, but only because she's super passive and chill and mostly indifferent to the words thrown to her, even though she's usually thinking on scolding him every time he curses because she knows he has to somehow improve on his antisocial behaviour. I'd believe they both meet each other in group therapy sessions and were forced to hang out together to work on their social skills
Isis is very neurodiverse and is overly aware of the surroundings, societal norms and social ettiquetes. She's also very vocal about it, as if she was pointing out sarcastically that all of it doesn't make sense to her, but ultimately she is not trying to offend anyone, she's well adapted. She might sometimes feel very alienated, or that she's constantly putting on an act publically, but at the end she's chill about it because she knows deep inside that she's still herself.
Despite the hostility Sev shows her, they both have their one struggle moment since they share species, and when two vultures gather together they can rant a lot.