These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Matron Yvonnel Baenre, the de facto ruler of the Drow nation Menzoberranzan, is also the most evil Drow yet seen. Yvonnel Baenre keeps the city in its dark, chaotic state while destroying Drow houses she judges have outlived their usefulness. Her own children live in fear of her, and when dealing with her most hatred rivals, the Oblodras, Baenre annihilates their House, sending every inhabitant, even the slaves, to the Abyss to be tortured eternally. Baenre's ultimate goal is to conquer the dwarven kingdom Mithrill Hall, and for this end, she has enslaved the soul of its first king for two thousand years. She also utilizes her Illithid ally to forcibly and painfully mentally torture and devour the minds of those she wishes to interrogate while allowing her children and house to torture those who catch their eye. when she assaults Mithril Hall, her goal is nothing less than the deaths or enslavement of all in her path.
Vendes Baenre, one of Yvonnel's daughters, is just as fiendish as her mother and more monstrous than almost any other Drow. Known and feared for her sadism and penchant for Cold-Blooded Torture, Vendes delights in getting her hands on any possible victim without regards for their crimes. Vendes ruthlessly tortures Drizzt Do'Urden and reveals her reputation in Menzoberranzan is well deserved. Vendes is also known for torturing luckless male drow and turning them into agonized statues to adorn the paths of the drow academies as a reminder to what happens to those who forget their place.
Fridge Logic: Alright, this troper can accept that people born in a society of sociopaths can randomly be good people with aversions to senseless violence. But when Drizzt turns down sex with the priestess, he tells his sister that he "cares nothing for her". How does he even have the concept that sex and love go together?
It was more of a way of knocking her down a peg. The scene where it's said is during an orgy, where everyone was taking on people to show their status. The fact that Drizzt left his sister alone with no one to sex showed that she had no power as a priestess.
At the rate they kill each other, the Drow would need to reproduce like bunnies (or at least something close to a normal rate) to maintain a stable population. However, one Matron seems to, on average, produce about the same amount of children as a human mother—except spread out over a few hundred years. They could not maintain their population as long as they have, let alone grown strong.
Well, the killing rate is actually not that high. Among the over sixty houses, there is one ascension attempt every decade. And some sources imply the struggle among commoners is not as wasteful - at least the families are stated to be larger.
This troper 100% agrees with the fridge logic and thinks it should go on the main page. If the book had been written 50 years ago, Drizzt would probably be saying "No! It's immoral to have sex before marriage!" Add to that that there is apparently no word for "love" in the drow language, the closest one being something that means "selfish lust". So how Drizzt was even able to express his feelings is a mystery too. Unless what he actually meant was "I'm not attracted to her"??
To make things worse the sex=love concept isn't even true among Good elves sop even if you remove the power play elements he still shouldn't have any problems having sex with random people.
While he may not have the "sex = love" idea in his mind, being less sociopathic than the others COULD lead him to the "I just don't want to sleep with my sister" conclusion.
Are there multiple versions of the book? Because I never saw an indication that it was his sister that was propositioning him.
Vierna is just harranguing Drizzt about not submitting to the advances of a random unnamed priestess during the religious orgy thing (and leaving the room, that was probably not OK either). That she even has (occasion) to do it is only because the unnamed priestess is already in a trance (i.e. drugged off her arse) and doesn't even seem to notice.
When Vierna tracks Drizzt down after he's left the orgy, her robe is casually opened in the front. She assumes (wrongly) that all he wanted was a bit of privacy and begins to come on to him, which provokes his reaction of disgust. An earlier passage where Vierna can't stop staring at her newborn(!) brother's beautiful purple eyes, and is scolded for her incestuous thoughts by Matron Malice, implies that Vierna may have been secretly lusting after Drizzt for years.
It may have been some time since I read the book, but while it's true she was fascinated by his eyes, that certainly doesn't imply incestuous thoughts. The closest thing I can remember to an admonishment was "He's only a boy, Vierna, nothing special (i.e. stop loving him like a sibling, he's a vermin)." The only person who was admonished for incestuous thoughts was Briza at the end of the book, who mentioned to Malice that she would have liked to "use" Drizzt like Malice used Zaknafein.
Malice's words as best I can remember were "when he's older and those purple eyes fascinate you so, remember on your life that he is your brother." Possibly not incestuous, but immediately following this is Vierna's thought process on the hypocrisy of Matron Malice presuming to lecture her on proper behavior, as Malice herself had a reputation of being something of a sexual deviant by drow standards (although it's implied that promiscuity, not incest, was Malice's MO). Vierna then silently expresses a hope that Malice wasn't reading her thoughts at that exact moment, because thinking such gossip about a high priestess (true or false) was a good way to get yourself killed.