Holy water

Holy water is a terrain type introduced in No Heroes Allowed!. It's spawned through Prophecy when cast by Shamans, most notably Erika. It first begins in a Pneuma item, and hovers in place shortly before spawning. This can be prevented by tapping it with the God of Destruction's Pickaxe.

Effects

Holy water obeys all the regular laws of water flow and turns all monsters that touch it into Pure Breeds; this includes all aquatic monsters that may be in the water at the time. Naturally, it is among the most hazardous spells a hero can use. Because it follows the rules of water flow, holy water can also disrupt regular bodies of water by taking it down with it to lower levels of the dungeon; to avoid this, water should be kept away from the edges of corridors. Plus, like regular water, holy water can be frozen. When the Shaman that cast it is defeated, it returns to regular water.

Because it turns most monsters it touches into Pure Breeds, holy water is the only way to obtain Pure Dragons, Chaste Chests, Pure Slinky Whales, and Puritrees. It is also the only way to obtain a Harmunculus, which spawns when a runeborn monster steps in the holy water. While Sublimanoids are obtainable through holy water, they are more commonly found through fossils that have come into contact with any kind of water.

Counterplay

Because the threat of holy water relies on monsters being hit, it's sometimes possible to store holy water in a dug-out dirt pocket when the spawn location is confirmed, limiting the damage it can inflict on Badman's army. However, this often requires a large section of dirt to do so, which isn't feasible in tight corridor-centric dungeons. Thus, if playing through chapters where Shamans are present, it's good practice to widen the distance between corridors to 3 vertical blocks or more apart to achieve this. Should holy water not strike too many monsters, it can arguably be beneficial in later stages, turning into regular water.