Astarion has one of the more complicated backstories out of any character in Baldur’s Gate 3. He has been a vampire for two centuries working for a horrible man named Cazador, but managed to break free and eventually ended up on the nautiloid ship with you. The vampire’s story comes to a head in Act 3, where he can confront Cazador to stop his former master from completing a ritual.
This ritual allows a vampire to ascend to new heights, and Astarion has the option to complete the ritual for himself.
After the battle with Cazador and seeing all of the prisoners locked up behind bars, Astarion will have the option to complete Cazador’s ritual. While it seems like Astarion would be killed during this ritual, as his soul is tied to it, the vampire says he knows of a way around that. So, you are left with a choice: let Astarion ascend or deny his desires and let him stay a normal vampire. I’ll give you details on how both decisions turn out and which choice you should make in BG3.
Warning, there will be spoilers for Astarion’s ending in Baldur’s Gate 3 below.
Letting Astarion ascend in BG3
First up, let’s go with the most tempting route, which is to let Astarion ascend. If you allow him to do this, Astarion will kill all of the vampires that are glowing in red around you as well as the 7,000 vampire prisoners that you saw before meeting Cazador.
However, Astarion does manage to find a way around killing himself and ascends to fully complete the ritual. This grants him brand new abilities, some of which are incredibly useful in combat. Letting the vampire ascend also yields his best ending, in my opinion. Since he has become a stronger vampire, he’s allowed to continue roaming around in the sun, even with the tadpole gone.
The only repercussion to letting Astarion ascend is that you have to kill 7,000 vampires to do so.
Stopping Astarion’s ascension in BG3
The other way you can go is to convince Astarion not to ascend, as he would be falling for the same power that got Cazador killed. You can also play on Astarion’s heartstrings by reminding him that he would be condemning 7,000 vampires to death if he chose to complete the ritual.
It doesn’t take much to convince Astarion to abandon the ritual, and in the end, he’s actually grateful that you told him not to go through with it. After Astarion makes this decision, you then need to recommend what to do with the vampire prisoners.
In this scenario, nothing happens to Astarion until the end of the game. If you choose to destroy the Elder Brain and everyone’s tadpoles with it, then the ending cutscene sees Astarion dart off from your party due to the sun burning his skin. The narrator reveals you will likely never see Astarion again.
Of course, you’re at the end of BG3, so you don’t technically need to see Astarion anymore regardless. Still, I found that ending quite sad after spending over 100 hours with Astarion by my side.
Which choice should you pick?
In my experience, there’s no real harm in letting Astarion ascend. You gain some great new abilities, Astarion gets to become a stronger vampire, and he gets to walk around in the sun.
Of course, you are killing 7,000 vampires in the process. If you’re playing a morally good character, this likely isn’t the way to go. For any other characters, though, I recommend letting Astarion complete the ritual.