When the Monolith’s light disappears, the lands are covered in darkness.
Dark creatures can be found in hidden areas of some instances. They can also travel through the darkness, gather resources for the player, and sometimes bring back news from settlements.
Settlements have different levels of darkness. The higher the level, the more mutated the creatures become.
The new instance is quite difficult, but also interesting. Our tester and I could not complete it, but we still managed to get some loot. Our characters are not very strong yet, so that probably made it harder.
Creatures captured in Monolith Shards are very helpful here.
Here is a small preview of the mid progression.