Carissa has spent a lot of time worrying if she is loyal enough but almost none worrying if she is Evil enough. She's not squeamish. She doesn't refuse to report people out of misguided sympathy for them. She has whipped students who get bad grades, and practiced deadly spells on weeping prisoners. She is definitely going to go to Hell, and it did not really occur to her to specifically worry about how evil she was within the very broad category of everyone who gets sent to Hell. She hasn't heard of anyone getting in trouble for not being Evil enough. She hasn't even been threatened, now, with getting in trouble for not being Evil enough!
...and maybe that's the point. Because there's a kind of Evil built of pure, sharp, selfishness, the choice to be concerned with yourself, and not with any of the other idiots populating the world, the thing she told Keltham, Evil as prioritizing the self. She thinks she's perfectly adequate at that, if she does say so herself.
The devil wasn't like that. The devil saw her, spoke two minutes to her, and wanted to personally rip her into pieces. Because it'd be fun. Because, having seen her whole, destroying her would be more of a treat than destroying some other person. And there was a different, though she hopes no one noticed it, when she stepped into his circle and threatened him back. He was threatening her because he felt like it. She was threatening him because she'd noticed that if she didn't learn to play she was going to lose very very fast.
She is pretty sure, in hindsight, that every Evil thing she's ever done has been the first kind, the weaker kind, the Evil of choosing Carissa Sevar over every other person in the universe. She feels entirely unapologetic about all of that Evil; certainly no other person in the universe is choosing Carissa Sevar over themselves. And if they were, that'd be stupid and contemptible of them.
And Asmodeus is saying that that's not enough. Well, it's clearly enough to get into Hell. It's not enough for the nature that devil possessed, not enough for her to actually succeed at the problem she has somewhat audaciously set herself, of explaining theology better so people aren't afraid of not understanding it any more than they're afraid of not understanding math, so they glimpse the outlines of the big, real thing there, even if that's all they glimpse.
'Acknowledge the desires in yourself that have no place in Axis'. Mainly it's the ...desire to be on the winning side, coupled with the conviction Axis isn't it, but she's pretty sure that's not what He means. What was it the devil said to Elias?
She should write that down too, she's going to need to use it to argue for a headband.
"Asmodeus's Queen and her slaves need not concern themselves proactively with Carissa Sevar's descent into cruelty, wickedness, and the darkness of her own soul; but if Carissa Sevar seeks to indulge of her own accord, she is to be prioritized for support as though she were the inheriting daughter of a Count of Cheliax."
It's embarrassing, but she never until this point considered that prominent leaders might be so cruel and wicked because they specifically got training and theological education in it, because it is part of what it means to be a servant of Asmodeus. Probably you can't offer that to the whole country because it won't run well if everyone's going around trying to develop their capacity for cruelty and wickedness. But you can offer it to the person who is trying to reform all of Asmodean theology.
All right, what's an action plan for learning cruelty and wickedness and the darkness of her own soul. Possibly it makes sense to start by observation? She watched Contessa Lliratha and knew that she wanted that, wanted to grow up to be that, with an intensity that would have carried her through murdering lots of innocent people, which isn't quite the thing, but it's a start. ...possibly it makes sense to start by asking. She has specifically been told that she can get support, if she only asks.
There's another thing she needs to master, here. The other thing the devil had that she didn't was presentation. Carrying himself in the world like he did things for his own reasons - and of course they were Asmodeus's reasons, he said it outright, but - but he carried himself like he was enjoying every minute of it. Carissa carries herself like she's loyal and competent and pretty sure she is getting a good grade, and that's not how to get a good grade in wickedness. There's a reason Asmodeus said 'the desires in yourself that have no place in Axis', rather than just 'acquire some desires that have no place in Axis', and she doesn't think it's because she has a secret kink for torture, she would've noticed that. It's because that's a way you can relate to Evil, not as some habits of mind for the defense of the self under threat but as the delight of the self in pursuing all it pleases, and in serving those who have even more power to do that -
I am ever your obedient servant, she thinks at Asmodeus, though it feels a lot scarier now that she knows there's a minute chance he's paying attention.