[He watches him for a long moment. The vibes are sympathetic, but resolute.]

Then take it, Astarion. It was not Karlach's fault nor your own what happened to her. She left you with the opportunity, and she would certainly want you to reap the benefits of having to go through with something she likely never wanted you to feel like you had to do again.

It was awful, but in the end... you saved her, and... she saved you.