A new dimension "Darkness" added.

1. The "Cursed Lands" biome has been moved to this dimension; it no longer appears in the Overworld.
2. The dimension is in a state of eternal night.
3. The coordinate ratio relative to the Overworld is 1:2.
4. Animals do not spawn.
5. Hostile mobs spawn at light levels of 10 or lower.
6. The surface light level is 0 without additional light sources.
7. The use of Respawn Anchors is prohibited.
8. All ores capable of appearing in Deepslate are generated.
9. The Darkness can be accessed via a portal.
	9.1. The portal is constructed in the same way as a Nether portal.
	9.2. Bloodrune Stone is used for the portal frame.
	9.3. To obtain a Bloodrune Stone, you must use Purified Blood on a Rune Stone.
	9.4. The portal is activated using a Darkness Key.

New mob "Shadow" added.

1. Spawns rarely and only one at a time.
2. Completely invisible at a light level of 6 or lower.
3. Extremely high base movement speed.
4. At a light level of 10 or higher, movement speed decreases by 16% of the base speed for each light level.
5. Capable of climbing to a height of 2 blocks.
6. Cannot be knocked back.
7. Invulnerable to most types of damage, except for damage dealt by players, fire and tridents.
8. Makes almost no sound.
9. It is not washed away by the water flow.
10. Takes no damage from Devouring Sand.

New mob "Rotting Walker" added.

1. Spawns only near water and toxic water.
2. Is immune to potion effects and drowning.
3. Takes no damage from Devouring Sand.
4. Has 2 points of armor.
5. Can break down doors.
6. Rapidly regenerates health while in water or toxic water.
7. Can launch a rot projectile at the player no more than once every 5 seconds.
8. Upon impact, the projectile applies Corrosion for 10 seconds.

Corrosion effect added.

1. If armor is equipped, it reduces the armor's durability based on the effect level.
2. If armor is not equipped, it applies a poisoning effect with the same to the Corrosion level.

Other Changes:

1. Silver and tin ores in a deepslate variant added.
2. Experience drops upon mining tin ore removed.
3. Sounds associated with interacting with Dark Iron Ore changed.
4. Rune Stone texture changed.
5. The blast resistance of Toxic Water reduced to 5, and its opacity increased.
6. Information about Weighting added in JEI.
7. Description for Upgrading Table added.
8. Now Smoldering can break down doors.
9. Group size of Jumping Zombies reduced from 2–4 to 2–3.
10. Ghost no longer takes damage from Devouring Sand.
11. Jumping Zombie's jump power reduced by 15%.
12. Bug where mobs lost their pathfinding when entering water fixed.