Something else to keep in mind is that- Eleanore is arrogant, high handed with all that her that implies.
I'm not so sure self righteous fits however.
It's hard and it's thankless and it means having to put up with a lot of very, very, very stupid people. But…"
I said earlier that Eleanore was empathizing in an arrogant manner with Louise and here's were you see the empathy. Remember Eleanore will challenge people to duels for being wrong. The above is heavily implied to be how she personally sees being good.
Which given that she's not belittling Louise for being weak (stupid yes, very much so. It is
Eleanore and she's very mean) Eleanore sees being good as by her mother's definition as being difficult.
She also is very aware of her family's past. She was the one that accidentally let out the Bloody Duke which led to her sister being turned into a vampire. And if implied to feel guilty over it.
Eleanore paused, "… and a vampire serving her."
And honestly I'd be surprised if some of that self confidence wasn't an act.
Callouses from wand use. Bitten nails.
Eleanore bites her nails. I have yet to know anyone with bitten nails that didn't do it as a stress response.
Which also brings up the consideration that some people react to stress by
a) lording themselves over people
b) being as mean as hell
"At the heart of it, Eleanore, there is Good and there is Evil. There is right and there is wrong. And though Evil will try to tempt you, you must stay strong and resist its blandishments. Your father's heritage is as wicked as it comes, but he stands strong against it – and so can you. I believe you will be able to do great and Good things, my dear, if you can resist the easy compromises of sin. I expect nothing less of you! And on that note, I also expect that you learn how to prepare your own potions to inhibit fertility and prevent infection well before you are old enough to need them, because sometimes accidents happen when adventuring far from potion suppliers alongside dashing young heroes. Not that I am calling you an accident. Even if you were one."
– Karina de la Vallière, speaking to her 14-year old eldest daughter
Eleanore was old enough to recall what the family home was like before her parents killed/rekilled half the staff. And said parents include a mother that puts down the choice of good and evil as very black and white. Who also will straight up tell her daughter to her face that she's an accident.
If any of the daughters were to develop a complex around not being a villain Eleanore would be the most likely due to seeing what her family can get up to, her parents response to that, then compounding it by being why her sister got vamp'd.
