Thoughts on the scenario after completing "Hammers of Fate".

I have another question: remember the cutscene from the Lords in the final mission for the Orcs, where Alaric talks to Biara in the guise of Isabel, and during the conversation, Biara loses her form and transforms into herself (a succubus). After that, Alaric runs away and says something like, "How could I? I served a succubus, I betrayed Erathia," etc. And yet, after that, as if nothing had happened, he leads his army to attack Gotay. How can this be explained? Was his brainwashed so much? (Sorry if the question is not entirely relevant to the section).