In my opinion he always wanted it and whatever was going on in Cazador's palace didn't change that. From the moment he hears about the ritual, he starts getting ideas to snatch it from Cazador. The fact the game forces you to persuade him to change his mind (and the roll is rather high too) is a gameplay mechanic that already shows that it was his actual decision. He consistently desires to achieve a specific outcome, no matter what choices you make in the game. It's also very eye-opening that if you kill Cazador without him, the first thing he complains about is not you killing his archenemy on your own, but you robbing him of the opportunity to become something more than just a spawn. He also blames you for sentencing him to an eternity in darkness and the conversation mostly revolves around the ritual. Him mentioning wanting to kill Cazador is clearly seen as a secondary priority to him.
Also, putting myself in Tav's shoes, I realize that my first decision to take the persuasion test (although the difficulty was low, only 15) was primarily due to a "metagame" mindset based on familiar stamps - "good deeds should lead to a good outcome", and I was afraid that in the case of Ascension, Astarion would suffer some kind of punishment for it in the story during the game. But truly living in that world Tav, who has no lines in front of her eyes showing where she can "roll the dice" and no idea of any "classic scenarios", would never have risked Astarion's fate like that, knowing that without larvae he would be burned by the sun, knowing his constant feelings of hunger, knowing he could be a spawn forever. She would support him, throwing away all her former "moral principles" that only work when you can afford it, and that in serious situations you should be guided solely by logic. She would have consoled Astarion near the cages, saying that it wasn't his fault, that it was all Kasador's fault (alas, I can only do that now in the next playthrough). It turns out that Ascension is Astarion's true, real desire, and also choosing this path is a truly "natural", "living" way of going through the game.
I just can't shake off the feeling that Astarion and Cazador already had a past that involved some type of rivalry before they became "a family" and it's a story that's begging to be told. Astarion sounds cagey and dismissive when he talks about his magistrate past. Cazador made particular effort to try to break him, enjoyed torturing him the most, wrote a lot about him in his journal - the man was evidently obsessed. I'm sure Cazador also saw similarities between them and it was driving him nuts - he'd never admit it but instinctively he must have felt threatened by him despite having all that power over him.
Yes, Cazador orchestrated the Gurts situation to get Astarion, it's unclear what his motives were for that? If there were no special motives, then we can assume that Astarion was a kind of "mistake" of Cazador (that's why he tried so hard to break him), and after Astarion, Cazador chose his victims more carefully, studying them better and making a kind of "psychological portrait" - stupid Petras, trusting his master, submissive and frightened Daliria (tried to do something with blood transfusion, but it failed and she didn't make any more attempts to save herself). We know next to nothing about the rest - the "favorite spawn" Leon, whose daughter Cazador held hostage, may have been the best, but that was balanced by having effective "leverage" on him, Violet, who liked to put garlic on everyone and giggle (which doesn't indicate high intelligence either). Apart from Astarion, the only other smart one was the former manager, who figured out how to fake his own death (we find him in a coffin, sort of "dead", but I think he woke up later and escaped) - but he was turned by Cazador in an "emergency" to replace Astarion.
The revenge on Cazador was immensely satisfying for both Astarion and me as well. The way it played out was also interesting and gruesomely intimate, because Tav and Astarion are literally in each other's heads and can see and feel everything the other does. It's not only him, but also Tav slicing Cazador up. His 'There... Perfect!' just sounds so damn awesome when he proudly admires his handiwork.
Indeed!!! That line just gave me goosebumps.... I can't remember another scene that impressed me as much as the Ascension scene of Astarion.
On the whole Inheritance thing: Velioth's scroll made me think that Cazador probably was the "black sheep" in Velioth's family, the one unruly spawn that was not easily dominated but tried to grasp for power himself. So Cazador got the special treatment from Velioth, which maybe in a sick twisted way can be called "tough love". The rules of vampiric existence (Always dominate. Power comes from solitude. Do not act in haste.) are considered valuable lessons for the vampires, so driving them home would make the spawn stronger - either a stronger slave or a worthy heir, should they eventually best you. Velioth seems to have taken his eventual defeat with grace. He seemed proud of Cazador to me.
Veliot may have been obliged to turn Cazador as a member of the Zarr family. Cazador also turned his niece (Lady Incognita, we find her diaries in the castle), but she didn't want that fate and ended up with a bad end. In my opinion, Veliot is a real, true psychopath who knows neither pity nor fear (he laughed when Cazador killed him), and Cazador is a secondary, "made" psychopath. If Cazador had any personality originally, it was completely erased and destroyed by Veliot; he is a "copycat maniac", fixated on rules that weren't even created by him.
Early-Game and Ascended Astarion is of course himself but he is very much Cazador's heir in his morals and everything else that he inherits from him - the ritual, the palace, the lifestyle and of course the rules.
Neither Veliot nor Cazador cared for the Zarr clan as such, which led to the clan's downfall. If you read about vampire clans on Faerűn, you'll see that the "one maniac theater" that Cazador set up has nothing to do with the rules of existence of adequate successful vampire families, where they have their own hierarchy and rules, but no such insane cruelty, and they exist and function normally for centuries.
Astarion is not a member of the Zarr family, and I believe the castle is a trophy, not an inheritance. Astarion is a new Ascended Lord who can start his own clan. Veliot's rules don't work (except for "don't act in haste") - Veliot and Cazador are dead, and Astarion and Tav, whose strength is not in solitude but in deep unity, have won.
I'm sure that Astarion's "domination" will not prevent him from listening to Tav if she offers him reasonable things in terms of organizing and managing the clan, building the castle's defenses, etc. The "domination" even now happens in a playful form, more related to love games, and it's hard to say what the couple's relationship will be like in two or three hundred years - my guess is that they are heading for a full and deep merger, "when the two become one".
After his confession in act 2, he is basically convinced that you will sooner or later dump him because he has not much going on for him besides a whole lot of issues. So he is at least trying to give you the full romance treatment in your conversations as an incentive to stick around.
It also made me feel terribly sad next to the unascended Astarion. I opened my consciousness to him in the second act (although the embrace scene looks much more beautiful and touching, it's a pity that it's impossible to combine these two variants, "opening your consciousness" seems to me a more serious action, which allows you to show the depth of your feelings). If Tav doesn't want to live without Astarion, and he thinks she needs "some more stimuli", what to do about it? And after the Ascension at least there's an opportunity to prove something, because if you don't "give Astarion everything" he's not going to believe you worth a damn. He's a paranoid big-eared

By the way, the Ascended Astarion didn't care about the audience - it makes me laugh a lot how the companions in the background (especially amused by Carlach's facial expressions

) periodically crooked their faces when hearing his charming compliments to Tav.
The only thing I do dislike about that dialogue is, that you cannot thank him for the impact he made on your life in return. This might be difficult for a normal Tav but Origins (including Durges) would have reason to thank him for his support during their quests. - I can tell Mystra that Astarion is the reason Gale is still around, but I cannot tell Astarion. ;_;
Yes, this version makes Tav some kind of emotionless doll. In general, there are few opportunities to express love with the unascended Astarion, so much so that it feels as if the lines were written by a machine. Or it's done that way on purpose.
In any case, I also especially like this slightly more aloof tone he takes with you post non-ascension because it fits the overall bossy tone he has with Gale very well. XD (No, Astarion definitely isn't a damsel in that relationship.) In general he feels more natural after non-ascension to me, since being cagey about his feelings is what is natural to him.
I guess when you play the story of two characters with their own personalities, it gives its own flavor and it's a slightly different perception than when you "launch your 'cooler' alter ego into the game". Everyone has their own story, their own character, they influence each other. You've mentioned several times how Astarion influences Gale's relationship with Mystra, and Gale's own path choices. In Tav's case, the story starts to revolve around Astarion alone, and the game is perceived a little differently.
He now embodies the rules of vampiric existence without regret and finalised his plan from act 1 to make sure Tav never turns from him. If Tav never rebels, Tav will never know. If the collar fits, it doesn't shave. It's a great dark ending - just a bit too real for me to enjoy as a fictional romance.
Oh, I really like this ending. I don't know what to rebel against - happiness and the possibility of being with the person I love forever? I don't see a collar, but a "guarantee." And when Astarion tells Tav "not to worry, she will always belong to him," I hear something like, "Don't be afraid. I will never betray you, I will never abandon you. I will always be with you." Just in an " Astarion style" kind of way.
Yes, his personality is very multifaceted. He is very emotional and charming (that’s why we all like him), but also narcissistic and cruel and it cannot be blamed all on a trauma, how Ametris also figured out. Most people who get hurt by others do not feel a pleasure in hurting other innocent people or humiliate them afterwards. But Astarion e.g. approves and enjoys torturing both humans and animals.
"In the suffering of the lowly we find the consolation of our own suffering" (from Malus Torm's diary, not verbatim). Astarion loves kitties! (double approval when dealing with "His Majesty" in the Last Light). He approves when you take a little owlbear into camp and take care of it. He feels sorry for the hyena being bullied by the goblins ( approval for helping the hyena and "evil" approval for sending the goblin into the shadows, but he deserved it)
He is indeed most time very self-centered. (Even in the tender act 2 hug-scene, it depends on the options, but he is always talking about himself. When you ask him, why he slept with you, he says things like, „I needed protection“, and „seducing you was easy, frankly“, „you were a complication I didn’t see coming“ – really mean words, in my opinion, for my innocent good Tav, yet Astarion didn’t even say a word of „sorry“ to Tav. Imagine someone would tell you, he just slept with you out of purpose, to get a benefit from it, and there is not one word of regret. Astarion is still here self-centered. I really missed an option to tell Astarion: „Oh wow, wait! What you just said - hurt ME!“)
To be honest, it didn't offend me at all. During the scene itself this question seemed completely inappropriate to me, I was checking it "in test mode", I think Tav could have asked it later, in a calm atmosphere, just for the sake of interest. It seems perfectly normal to me that a person doesn't trust me at the beginning of a relationship, that I have to somehow show that I'm worthy of his trust, because he doesn't know anything about me yet. Especially Astarion, who has gotten nothing but pain from the world ("I prayed to them all. No one answered"). One could make a joke about how he "tried so hard for nothing" - I really wanted to protect him without any "vulgar thoughts" and a little later Astarion decides to give the gift of a night with him to get that very protection - funny coincidence
So, I myself, always saw Astarion as a dominant romance Partner. „On your knees“ and the insight check „He will always see you as degrading yourself if you continue to be with him. But perhaps you WISH to DEGRADE YOURSELF. And he KNOWS it.“ Gave me chills (in a positive way). People with special interests will not question his behaviour or the insight check. For us, there is nothing odd about it. It is really interesting how many interpretations of this insight check exists. I am lucky to just say: The storyteller is right!
Interesting! I had acquaintances who were passionate about this theme, and it was interesting for me to ask them to tell me about their philosophy - they told me, among other things, that it was "trust". At the time, I could only understand it at the level of logic, as a fact that some people see relationships that way. But in the case of Astarion, I was able to feel it - both trust and the feeling of happiness from the fact that you can give yourself entirely to the person you love, to give him pleasure. The "second time" I was able to do this, despite the fact that I was "broken" the first time. This is a completely new and unusual experience for me.

[In the main plot, both Astarions almost behave the same. Compared to how he behaved and approved in act 1/2 – where he had already evil traits - he doesn’t become worse, mostly prouder. I must say, I really expected and hoped him to become a bit more evil toward others, but „unfortunately“ or not, he is still very soft for being a Vampire Lord - hahaha. Well it’s okay. I love Astarion and Tav being in their Vampire-marriage-spawn-consort-slave-whatever relationship, they are deeply bond forever.
I was also expecting Astarion to start trying to "dominate" or "push through" his decisions at some plot points, but he doesn't. He doesn't do anything at all in any way "bad" or "evil" towards Tav.
I don't believe him when he says he doesn't remember it. He dismisses it as ancient history and says years of torment made him forget, which sounds like an excuse. It's in his interest to present himself in such a way that Tav would feel compassion for him and to do that he'd omit some naughty stuff about himself. If I recall correctly, Dalyria remembered her mortal life very well and wrote about it in her journal.
Yes, it's a pity that Astarion hides so many interesting things about himself... By the way, in the list of visitors who are not allowed in Theobald Torm's tavern there is mentioned an elf with a cheeky grin who called the innkeeper "pig-horn" (I don't remember the exact quote). Could this have been Astarion? It seems to coincide in time, and Astarion went to taverns (his trouble happened in a tavern where he was attacked by the Gurts).
In my game he opened Ketheric's chest and read the Chosen wife's letter to him and he was moved by it. It seems like he'd been entertaining the together forever idea for some time.
Interesting fact, too bad I searched the chest myself then, let's see if he reacts to the letter if he finds it in the chest at camp...
Frankly, his romance is never particularly healthy, doesn't matter which path, and he even admits himself that these relationships are not his strong point. But it's certainly succulent!
At the same time, Astarion gives such a huge return, such a strong affection in response to your feelings that if his relationship is "unhealthy" - it discredits all notions of "healthy relationships". I would call this relationship more of an "abnormal" relationship if you consider the norm to be not something good, but something most common and habitual. Like if a legendary artifact of divine power suddenly appeared in the shop of a blacksmith who sells well forged +1 swords - that sword would be "abnormal" for that shop.