Of all the potential redemption arcs Astarian and Gale seem the least likely to change.

Yeah, Astarian wants to become the strongest vampire lord in Faerun and it will be difficult to turn him from that path. But I think the wine scene really brings out the pathos in the character. The wine is excellent but he can take no pleasure in it. For him enjoyment only comes in the form of fleeting moments. That's the curse, he's been doomed to only find pleasure in the taste of blood and he has surrendered to that fate by developing a sadist's taste for cruelty. And now he's lost, no longer does he have a master to tell him what to do and, having defined himself against another for 200 years, he's struggling with who he is. Afloat in asea of misery he found isolated islands of pleasure in acts of seduction and of cruelty -- now he has found another place to anchor, will that be enough? He could use you as safe harbor to develop a taste for kindness or he could succumb to the fantasy that he will be happy once he becomes master and Cazador the slave.

Eager to see what happens with him.