The Nexus

The mad God Keeth, in his dying act, grabbed four planes and stitched them together with a fifth, Ravnica, being the center point. Jungles, floating mountains, rolling plains, all thrown together as a last bit of 'fun' for the mad god to leave in his wake. Denizens flowing from one plane to another, explorers, adventurers, and as always nefarious types are more than happy to take advantage of this sudden development. There are rumors of an ancient evil beginning to stir. But those are just rumors. Right?