After reading some of Brandon Sanderson's work it seemed he tended to have much more of a dark side in his novels than Robert Jordan ever had in WOT. It seems this dark side is going to be showing up in The Gathering Storm if the first chapter is any indicator, especially when it comes to the personality of Rand. At the end of Knife of Dreams Rand was shown to be hard and troubled. He now appears to have taken a very large step towards dark and instable perhaps even with a hint ,or more, of insanity in his future. This is a darkness that I don't think Robert Jordan would have employed. He always seemed to write with a balance that left room for debate in this matter and much of WOT as a whole.

The reason I think Brandon Sanderson has taken this approach is to show the desperation of the light. After all how more desperate can you get if your champion goes mad.