The Final Chorus

[Alberel]

I don't think Lahabrea wouldn't be involved in the situation because he got wiped by Thordan

Not necessarily. His physical body was killed and then his aether was absorbed into the eye on Thordan's sword. There's a great deal of speculation on whether it's possible he's still alive but trapped inside the eye (and thus now residing within Estinihogg).

I wouldn't be surprised if whatever we do to save Estinien inadvertently saves Lahabrea, assuming he is still alive.