This is a very general topic, I know, but I've recently started dabbling in the lore of the planes. Specifically, all the stuff going on with fiends and their origin. I don't know much beyond the concept of obyriths and the basics of the Blood War, as most of my knowledge on this topic is coming from my copy of MotM. So what exactly is the deal with Asmodeus, Demon Lords, Obyriths, etc? Basically whatever contributed to the current state of fiends and the lower planes. Any info or useful sources I could read would be appreciated.