The Dragon Empress and other Big Bads (Revisited)

[Revisiting and expanding on a post from, golly, 2009!] While not all campaigns have them, many do, the biggest of Big Bads: Dark Gods, Lich Kings, Embodiments of Primal Chaos, and other such insanely powerful beings (or, perhaps, a Dragon Empress).  You know the archetype.  His dark shadow lies across the land, the armies of…