I do think Astarion not being cured of his vampirism is the best conclusion to his story on a writing level, and I'd never change the existing endings, BUT it's so much fun to imagine how it might go if it was cured anyway (spawn ending of course).
Like, imagine being able to see yourself in the mirror for the first time in two hundred years. He probably knows what he looks like by the end of the spawn route because I refuse to believe he never asked anyone to paint him or show him with the tadpoles, but he's entirely missing the experience of being able to do it whenever he wants. So now he can actually see what his hair looks like while he styles it, and he can practice expressions in the mirror to refine how he comes across to others, and you best bet he's going to be a whole new person after a few hours (or just even more confident in what he already had!). Ascended Astarion spends a whole lot of time looking in the mirror, and I don't think Spawn Astarion would be much different (although his feelings about it might change a bit).
There's also the fact that he's like... mortal now. Sure, it was possible to be killed as a vampire, but it's frankly much more difficult, and during the events of the game, he had the added assurance of basically being able to be revived whenever. Astarion spends a lot of his development learning not to let himself and his decisions be commanded by fear, and accepting himself at the level of strength and power he is. A lot of that is social, but he is also very used to others having and exerting physical power over him, and wanting to take that control for himself. I think being turned back into essentially a normal high-elf would leave him feeling vulnerable, more than he was ready for, and he might regress a bit in his thought patterns.
He's alive now! Great! But in exchange for the sun and no longer having to drink blood, he has to wrestle with a way of being he no longer understands and that he feels is considerably weaker. He isn't a special elf necessarily, just a Baldurian with a once-cushy job and two hundred years' experience being a slave, and one who happened to become a hero of sorts (or not, I suppose). Even if he did have experience with fighting and such before he was turned, he hasn't adapted to needing to defend himself in the way mortals normally do. He can still kill, but a stab wound that would've been an irritation before is now potentially fatal. And he's died once before.
Even simpler things will be more or less brand new to him. There are some illnesses vampires can contract, and so many more they can't. His immune system won't be adapted to everything going around two hundred years after when he was originally alive. He'll be getting sick left and right, and he's unfamiliar with that kind of sickness too!
Meanwhile, he's entirely unused to simple things like having to eat every day and drink water. Before, he needed blood to keep himself strong and mentally clear, but not to survive necessarily. On top of that, you need to drink water and eat food far more often than vampires need to drink blood if you want to avoid severe negative consequences (... like death). I don't imagine this would be easy for him. I already think that drinking blood is a bit of a challenging thing for him mentally due to the deprivation Cazador had him under, but also the fact he was forced into drinking blood he didn't want (of rotten rats) regularly as well.
I've toyed around with the idea of him having disordered eating (blood drinking?) patterns, while still being a vampire. I think the lack of self control it inspires may be frightening to him, and that will only be enhanced by how long he went without enough of it. He'll have an endless drive to consume, stronger than it should be, but he isn't really used to being able to give in. It doesn't feel so different from Cazador's command over him, forcing him to feed or not to feed. Without his vampirism, I think this would likely manifest the same way, but with an added dimension of complete novelty. He probably doesn't even remember what enjoying food is like, only that he once did (the Elfsong's calamari, lol). He's going to be struggling with a feeling of deprivation while also feeling out of control, and he's also going to struggle with not being used to needing so much. Whether this results in overeating or undereating is another question, but in my opinion, it's both. Alternating.
On the topic of bodily changes, his body will visibly change. He'll probably still be pale, but not quite as. His eyes will change color. I can't tell if vampires are meant to be able to gain/lose body mass (I don't think they should be able to, but if you play as origin Astarion, they of course still have the line from Shadowheart about him gaining weight, and then he responds with something like "you don't want to know what I've been eating"... so idk). He'll lose his fangs, and he just won't look as threatening in general. That appearance he's so used to using as his main tool, or even as a weapon, is changed. He needs to adapt to that as well. Maybe this is good! He's trying to move away from that way of seeing himself, after all. But it's still uncomfortable.
And then, FINALLY: he will be able to engage in simple mortal joys. This is one of the main appeals of Ascension - being able to enjoy food, alcohol, everything to its fullest extent instead of relying on blood for everything. I think being able to taste wine again (and get properly drunk on it?) would be a big deal for him, as would being able to sample fancy dishes. The sun is another one of these things, something most take for granted but he has only ever experienced on a time limit. And unlike tasting food and alcohol properly, he's actually had a taste of the sun himself, so it would be a very welcome reunion.
This all is also why I think he puts so much emphasis on regaining his ability to walk in the sun rather than being cured. He seems passively fond of the idea of no longer becoming a vampire, but he wants to walk in the sun again (although he does accept being unable to, an important development!). Weakness against the sun is, to him, the worst aspect of his vampirism after Cazador's death. Ascension would've given him just about every appealing aspect of being mortal, with several bonuses neither high elves nor vampire spawn have, but if he doesn't choose it, all these aspects of becoming alive again are just hanging above him. But he needs to sacrifice the state of being he is used to and the strengths he has come to expect if he wants to become his old elven self, who he doesn't even know anymore.
Anyway. Long ramble over. I have more thoughts on this topic, but I think I'll leave it off here.
Sorry everyone back at it again with the Gale Blowjob thinking but I think we should be able to give Gale a blowjob infront of the Mystra statue in the same way we can have sex with Astarion on his grave.
