Darkness its a kinda like in the sky and it uses mycelium to grow it the island grows overtime in the sky

Darkness its a kinda like in the sky and it uses mycelium to grow it the island grows overtime in the sky

So let me try to interpret.

A "darkness" biome. Similar to the sky biome, but with mycelium. It consists of sky islands, just like the end does, and the mycelium grows, and forms new mycelium blocks over time, causing the islands to grow.

Being darkness, instead of light, it would have undead monsters (so the various "die in sunlight" mobs would spawn more frequently than normal / more frequently than other mobs). Equally, there would be some sort of darkness effect that prevents direct sunlight from reaching the ground -- so perhaps in addition to mycelium on the ground, there might be some sort of light (as in not heavy) leaf or other shading layer growing, not much, just enough so that the light on the ground is skylight 10-12 instead of 15. (Example: Leaves three-five spaces off the ground, kinda like a forest canopy that is not a thick canopy).

Or, perhaps it is a thick (or just tall) canopy in places, so the mycelium is really dark. Then, even in full daylight mobs will spawn.

In some sense, this is kinda like Twilight Forest, just with vanilla (or mostly vanilla) stuff, and only a surface/sky island issue.

(side note: Twilight Forest has a really interesting underground ...)

I'm sorry. This is not detailed enough.

Like the sky and hell "biomes" this is really a world type.