Otherside: The Sift

n unofficial fan project inspired by Minecraft Dungeons II — not affiliated with Mojang, Microsoft or the makers of the game.
Builds: Forge 1.20.1 and NeoForge 1.21.1 (same features on both; mod id mcd2_the_sift_dimension).
Everything is early / experimental: report bugs, they are fixed fast.

THE SIFT
A new dimension of sculk-grown hills, glowing caves and Ichor — a dangerous living liquid that burns like lava but is not lava (other mods are not confused).

• Three surface biomes: Singer's Meadow, The Carapace (sand and fossils) and the tall Lullaby Hills (pink grass, Sift trees).
• Underground biomes by depth and humidity: Ichor Caves (flat ichor lakes, crystal towers, ichor kelp, tiny ichor puddles and schools of ichor slime-fish), Hollow Gardens (a whole red-sculk cave with grass floors, hanging sculk vines, plants and the Sniffer) and Infected Caves (a Deep Dark-style biome with sculk veins, sensors and shriekers).
• A day of its own — the Tides. No sun, moon or stars: the Sift runs a 20-minute cycle of three "hours" — Thrive (morning), Flow (day), Endure (night) — with their own pastel skies, light and mob mix (more passive mobs in the morning, an even mix by day, more hostile mobs at night). /time set sift thrive|flow|endure and /time query sift (it never touches the overworld clock).
• A sky drawn from scratch: a gradient dome with colour shades round the horizon and soft pastel clouds.
• Return portals that you find closed in the Sift and bind to an Ancient City portal; a ritual and the Singer's Flute to call the Singer.

MOBS (ANIMATED MODELS TAKEN FROM THE GAME'S OWN DATA)
Over 30 mobs: the Sift's flora and fauna (Slabber, Nuzzle, Blub, Pollinator, Wild Sentinel, Sprout, Bloombud, Tuner, Wobble, Lootkin, Echo Golem and more), the Singer, souls, and the Sculk Stalker / Scavenger family. Bosses: Sculk Monstrosity, Monarch, Supreme Evoker, Monstrous Opus, Prime Enchanter, Copper Monstrosity, Twisted Warden. Boss bars only show when you are close.
Optional support for the author's own illager mod Eternal Shard: Illager Rise (its illagers appear in the stronghold when that mod is installed).

STRUCTURES

• Illager Stronghold (Lullaby Hills): a plaza with the Illager portal and the boss fight, long roads with crossroads, corners and dead ends, small wool paths to armories, ravager pens, a sifter cage, barracks, a forge, mess hall, prison, watch post and storehouse. Ichor pipes and chopped Sift trees all around; illagers keep spawning inside; barrels and chests carry loot from outposts, mansions, ancient cities and the Sift.
  Supreme Evoker is called by a trigger on the plaza; the dormant Monstrous Opus waits there and awakens when the Evoker's Soul Block flows into it.
• Base 2 — the ice keep of the Prime Enchanter in the overworld's snowy biomes; the boss rises when you enter the hall.
• The Copper Tower on the plains: stone bricks and waxed copper, a winding stair and a big platform with the Copper Monstrosity on top.
• Boss arenas for the Sculk Monstrosity and the Monarch (sealed chambers opened with a key — carry a Tuner on your shoulder).
• Closed Sift portals, fossils, ichor pools, soul trees, key vines and more.

ITEMS

• Sculker Claws (dual claws, drop from the Monarch), Resonator (sonic beam artifact, drops from the Sculk Monstrosity).
• Soul Block — an item that is a bag of souls: its durability is the souls it holds. Right click opens three symphonies (name and cost only); shift + right click places the block or hands it to an Echo Golem. Creation symphonies (need the Emblem or the Friend of the Sift effect): Creation, Breath of Life, Rebirth, Choir of Healing, Sanctuary. Destruction symphonies: Soul Storm, Soul Wrath, Collapse, Rift, Annihilation.
• Memory Crystal — gathers souls and returns part of your inventory after death.
• Three talisman slots next to the player model (also in creative) and seven talismans: Emblem of the Sift, Ichor Diver, Souls, Sight, Tides, Gardener and Featherfall
• Spawn eggs, Sift wood set, plants (the Sniffer can dig torchflower and pitcher seeds on the Sift's grass) and a lot of building blocks.

SHADERS
Includes our own from-scratch shader pack MCD2 Look (MIT licence). (upload soon.)

COMPATIBILITY NOTES

• One mod, two builds: use the Forge jar on 1.20.1 and the NeoForge jar on 1.21.1; do not mix.
• Works with other mods; Ichor is not in the vanilla lava tag on purpose.
• Needs no other dependencies.