«I broke my chains» - who else but Astarion could have broken the chains?
Lae'zel. In fact, isn't there literally a quote about Lae'zel breaking her chains? From Vlaakith.
Shadowheart. Breaking her chains from Shar.
Wyll. Breaking his chains from Mizora.
Dark Urge. Breaking his chains from Bhaal.
Karlach. Breaking her chains from Zariel.
Gale. Breaking his chains from the orb.
It's a theme throughout the entire cast of characters.
