Complex sentence: His own men typically seem to be terrified of his mercurial nature, as they are wholly unable to predict his violent, dark moods and impulses, their fear is justfied as Gregor once killed one of his own men just for snoring too loudly.
Split into simpler sentences: His own men typically seem to be terrified of his mercurial nature, as they are wholly unable to predict his violent, dark moods and impulses. Indeed, Gregor once killed one of his own men just for snoring too loudly.