Creeping Chill

In snowy biomes a torch or lantern placed in the open can turn into its soul form. The conversion depends on the land being cold enough for snow, the area being dark enough for sleep, and the light source having enough exposed sky light, with soul lanterns favored outside during thunderstorms. Biome bounds are described as fuzzy and imperfect, so results near edges can vary. Village torches and lanterns already generate as soul forms during world generation where the conditions apply. Fire light sources placed in soul sand valleys are converted by default, and a data pack can mark another biome through a biome tag so its fire light sources always convert.

Creeping Chill also exposes a dynamic registry that lets other datapacks define their own fire-to-soul pairs. The example in the author text adds redstone torch to soul torch, written as a JSON file under a custom namespace. Vanilla pairs such as minecraft:redstone_torch and minecraft:soul_torch already exist, so they cannot be declared again in the same way, and blocks added by other mods can be registered as long as their own mod is installed. The mod is published on Fabric only, requires Fabric API, and runs on client and server for 1.21.8, under the ISC License as open source.