Black City

The Black City(a.k.a. Shade's Keep, Dark Nostris) is a nearly pitch dark version of Nostris Lux in the plane of shadow. The city is surrounded by a seemingly endless black plain. Humanoid shadows aimlessly wander the streets, attracted to light, but harmless. Dark Hounds can also be found in the streets sleeping on the ground in higher numbers as one approaches the Tower.

Black rivers of sludge pour out from the Tower, full of concentrated foulness filtered out from the sewage of the city. Touching the sludge will make one sick. Consuming the sludge can be lethal but if survived confers an immunity to poison and other foulness.

The buildings are non-reflective featureless boxes, many of which house trapped demons. The Tower contains Tenuit Tenebris, the demon chained by the ancient hero Petra Mortis prior to the founding of the city.

Effects of the black water
Mere contact with the water in the Black City is harmful, dealing damage every round until it is washed off. A covered extremity deals 1 damage per round, a covered limb deals 1d4, complete submersion deals 2d6

Consuming any of the black water inflicts the imbiber with the poisoned effect and deals 1d10 necrotic damage per hour. Each hour, the imbiber can make a constitution saving throw, starting with a DC of 28 which decreases by 2 each hour. Upon succeeding this throw, the poisoned effect is ended and the damage decreased to 1d4 per hour, and the save DC is reset to 26, a second success reduces the damage to 1 per hour and resets the DC to 24. A third success ends the effects of the black water and gives the imbiber shadow affinity.