koren is a damn maniac so don't feel bad about not killing him. I'm only partway through but I'm impressed with this mapset. 1 and 2 felt kind of "classic doom/dungeon crawler" to me which isn't my preference but 3 and 4 really cook. I've enjoyed all the setpiece fights very much, especially the arena that keeps getting partitioned off after either key in map04. Really cute and creative, and keeps you on your toes without being too strenuous.