People around here realy should try using search from time to time. -_-
The advanced search returned 3 previous threads with "ceremorphosis" in the topic. The
first was a debate on if the story made sense, but didn't mention solutions. The
second was about how it might limit race selection to humanoids but wasn't about plot holes. The
most recent is actually linked to in my first sentence. I commented in that post
"In regards to how I would handle it... I will make my own post as I don't want to hi-jack yours." That post was the inspiration for this one, or I should say, my quest to find a solution. Is there a rule against posting on the same subject here? Last I checked, this isn't stack exchange. If anything, it brings more attention to the issue.

So here I wanted to suggest a budget friendly solution and explain why I think it is the best.
From my point of view not letting the chars die is the most easy way to plug this hole. PC death is really unnecessary...
This would also be my preference. After all, BG1/2 didn't let companions die on normal difficulty. But dealing with Gale is a pain in that case. It can be done (I even suggested 2 ways of doing it in my original post that I edited heavily), but it bulls down to making changes that would require many more development hours and resources than pasting some text into an existing book. So I agree with you, but I am favoring low budget fixes as I feel those are more likely to be entertained.
Are we sure it's a hole? Perhaps more is to be revealed in later acts?
I am not dismissing that possibility. And I like debates. But as pointed out earlier in this response, there are already threads where the question is being or has been debated. I prefer to focus on solutions with the assumption that it is a hole. The way I see it, if it's a hole, Larian might find a thread dedicated to possible fixes useful. And if it isn't a hole, I'm sure Larian will just ignore the thread anyway.
