I got the Molag Bal quest in Skyrim, where he wants me to lead the priest to his altar and then kill the priest. When starting this quest I felt certain that there must be, at some point, an option presented to betray Molag Bal and side with the priest instead. He's the god of betrayal/treachery after all, isn't he? So it seems fitting that there would be an option to betray him.
However it seems like no such option is ever presented. Is it possible to side against Molag Bal, and if so, how? If not, then isn't this quest pretty much broken? I mean, what's the option for playing a "reasonably decent" character if there's no way to refuse the god of evil and betrayal once he has you in his web?
Best Answer
I shared your idealism for a while in the game but soon found out the game is just not perfect and even though it goes really deep into details and give the character lots of freedom, it does have its limits.
Quests have fixed rules - the only way that exists (in most quests) to break out of the "chains" posed by these rules is to kill some key character - as also mentioned in this answer the key character in your case is the poor priest himself. This cause the quest to fail instantly however you won't get any further feedback about that - the game simply didn't go as far as that.
One more example demonstrating the game limits is that when you go without any cloth or armor near people they will occasionally say something along the lines "Get dressed!" but that's all - they will never actually do anything about that and you won't get arrested. It's all bells and whistles. :)