After Astarion freed the spawn not completing the ritual, you find Sebastian, his ex, sitting outside of Cazador's lair, his eyes stuck in the distance.

The newly free vampire notices your approach, his eyes widen for a moment as the words lack, but he manages to speak after a few seconds of silence. "I…Uh…" He starts, sighs and scratches the back of his neck before proceeding. "I guess I should introduce myself properly now, I'm Sebastian…I don't think I remember my surname though…"