1. I also encountered the game freezing on the Purple's turn on 5-2-5.
2. And on 5-3-4, I encountered cheating AI hero flight (also Purple): Prospector confirms the suspicion that Sephirophor has neither spells nor artifacts that allow flying.
Problem 1 is solved by using HD+, problem 2 is solved using SOD_SP.
3. Trying to reach the green tent from the Griffin Conservatory at cell 95,105, I found I couldn't get there. A question for DarkT1me: how did you get through this area? I'm going to look in the author's video recording now to see how he got through there. I don't necessarily need to visit that tent yet, but I have already visited the white and black ones to get to Purple, took the Vampire's Mantle, and want to pick up the Amulet and Boots to put together the Cloak of the Undead King, then I'll chop down the liches and invade Purple.
(Василь Симоненко. Люди – прекрасні)