My coop campaign was having a lot of trouble keeping Isobel from being captured and didn’t want to have to wipe out everyone at last light in due to the shadows etc etc. We succeeded in killing Marcus but the horrors can abduct her anyway if she gets paralyzed.
Finally, on the 3rd attempt we thought what if we try something way out of the box.
We had one invisibility potion, and Shadowheart had the spell command. Commanded Isobel to flee, and threw the potion onto her causing an invisible Isobel to run off and hide for 3 turns while we mopped up Marcus and the other enemies as fast as we could.
The plan worked and now we have Selune’s blessing AND everyone at last light is still alive and well
You have to test the barricade by trying to go through, if it says you can’t go there, all is good. I believe you can block the side balcony but not the one Marcus comes through.