Path of the Fallen

Walkthrough of the "Path of the Fallen" scenario on hero difficulty: https://www.youtube.com/watch?v=E9d3b_1V6jI

Added 4 minutes later

I played until the point where the captive is guarded by 20 druids and about 20,000 archers. And I only have one succubus. Naturally, a new dialogue option with the guard did not appear, so I had to fight.

During the dialogue with the druid (before the battle), another action option should appear. This will not happen if you remove the attached succubus to the reserve even once. I did this once, and I had to replay, thankfully I save every 3-6 turns.