Demon of the Well
Map 11 -- Execution - 100% Kills / 100% Secrets
This is a bit of change of tone. Depicted is a grim redrock/bloodlands hellscape with some uninviting industrial touches, dotted with unwholesome infernal vegetation and a variety of gallows and trees-of-woe from which hang mutilated corpses like so many fruiting bodies. The use of 'Demons on the Prey' also helps to establish more of a sense of foreboding than the relatively lighthearted aspect of previous maps (and of at least some maps to come, honestly), but in truth I think the one thing that makes the level feel oppressive (more oppressive than it actually is in terms of threat/challenge level, honestly) is simply the opening minute or two--start off by instantly taking 20% damage (if not more) in the obvious Duke3D homage, and then face the single most dangerous fight in the map seconds later.
There's a pretty ideal/consistently survivable way to handle this, of course--don't stand your ground, break right as soon as the wall is down, and haul ass towards the little side-building with a plasma rifle, soulsphere, and a (useful for a change) blur sphere--and a number of less ideal but also survivable alternatives, but it will likely spell a quick and violent death on first contact, which sets the emotive tone for the map.
It's really not all gloom and doom, though--far from it. Despite the generally macabre environment, several iterations of characteristic KS zaniness show up to lighten the mood a bit, from the silly velour skull decal on the revenant pagoda to the batshit-crazy action-hero exit sequence. Similarly, if you can survive the first 60 seconds, it's really not a terribly stressful map from a combat standpoint. Sure, there are a ton of demons, but there are scads of ammo (particularly rockets) and other supplies, as well, and the only other real trap (where revenants appear from behind a lowering wall with a well-shielded arch-vile at your back) can be easily backed out of. Some characteristic monster/blocking line foibles do show up (e.g. the immobile imps on the bridge, the monster-blocking line in the alley leading to the plasma rifle building, etc.), but they're less obvious/intrusive than in several of the past maps, and don't dampen the experience too much.