I done all main quests but the final one again and golden tower side quest, and I still don't get any scene when I return.
Fuck this game.
Thanks for the help anyway.
You are lucky you have me. ;3
So, I've checked my saves and found out that I have dedicated save only for the final Mom+Mar+Hero scene. "Bummer!" I thought - and decided to make another save for the penultimate scene with Mom and Mar. Also, to figure out what triggers it.
First task was a resounding success, so here are two saves. Save 8 is for penultimate scene (Mom+Mar), Save 16 is for final scene (Mom+Mar+Hero).
Second task was half so. You see, I've speculated that finishing quests itself triggers the scene - it does not. I have done all of the Golden Tower quests and still got nothing. "Bummer!" I thought - and did penultimate Act III mainquest as well. Was greatly disappointed because it didn't work as well!
So, the core of the issue was sleeping - you have to sleep in your room in the Castle to progress the scenes. And so my test failed, because I've tried to sleep only after a lot of quests. Maybe, I could have save a lot if not all the efforts by simply leaving Slinsk, sleeping in Castle then visiting Slinsk again. I don't know. Maybe what it takes is exactly the steps I've taken, may be only a part of it (like a single step of Golden Tower quest or something similarly small), may be quests aren't necessary at all! You can try the latter option since it would take you aroud 2 minutes to do so. As for me - I am kinda tired doing all of it.
But a good find nevertheless. I was so used to frequently sleeping at Castle that it took me awhile to figure out this seemingly ordinary action makes such a differense - and yet it does! Honestly, should have figured it earlier, since I've already had a feeling that some of scene sequences played through very different intervals that logically shouldn't be the case. But it was a vague suspicion until I tested it just now. The more you know!
So, to everyone - sleep at your room in the Castle if you wish to progress scenes. Questing and visiting locations is not enough or may be not enough.