Ancient Core — The God Beneath the Ancient City

Deep within the Ancient Cities, something was sealed away. Touched by the power of the End, it has awakened. Forge a key from the Warden’s horn, open the gate at the heart of an Ancient City, and step into the Abyssal Rift — where a floating god with a single violet eye is waiting.

A boss mod for Minecraft 1.21.1 (Fabric). Three phases, 40+ attacks, a dedicated arena and battle music, and a rideable companion as the reward. Tuned for cooperative multiplayer (2+ players), but playable solo.

How to begin

Defeat a Warden — it always drops a Warden Horn.
Craft the Abyssal Key 4 Sculk Catalysts, 4 Echo Shards, 1 Warden Horn

   [Catalyst][Echo Shard][Catalyst]
   [Echo Shard][Warden Horn][Echo Shard]
   [Catalyst][Echo Shard][Catalyst]

Find an Ancient City. Throw an Echo Eye (Eye of Ender + Amethyst Shard + Bone) and it flies towards the nearest one, like an Eye of Ender. An Ancient Compass (Echo Eye + Compass) always points to it.
Use the Abyssal Key on the reinforced deepslate frame at the city’s centre. A violet portal opens (the key is used up).
Step through into the Abyssal Rift. The god sleeps on its altar. Come close and move, and it wakes.

Ancient Cities lie deep underground (around Y -51). The Abyssal Drill will bore a shaft straight down for you, given fuel and a pickaxe.

Features

Three phases, 40+ attacks. A close-combat first phase, a second phase where the god splits into eight, and a final form that rises again after you thought it was dead. Every attack has its own counter; running in circles won’t save you.
Readable telegraphs. Red warnings cannot be blocked. Purple warnings can be blocked with a shield, but hit harder.
The Abyssal Catastrophe. Once, at 25% health, the god unleashes a 40-second, seven-act ultimate. The music dies and only a heartbeat remains. Meteors, dimensional rifts, a cage of lasers, wandering safe circles, and a final detonation that only the altar survives.
A dedicated arena. A floating arena in Ancient City style. Nothing in it can be broken or placed.
Battle music that grows heavier with each phase. Strings, choir, brass and war drums, then total silence during the ultimate.
Built for multiplayer. Health scales with players (+50% per extra player). The clone ring forms around each player, and rewards drop for everyone who fought. The god switches targets unpredictably and favours whoever is wounded.
Fair resets. The moment no living player remains in the arena, the fight resets. Rematches rebuild the arena from scratch.
An Ender Dragon-style death. The god breaks apart over ten seconds and scatters around 4,000 experience.
11 advancements.

Phases and attacks (highlights)

Phase 1 (100–50% health)

Attack	What it does	How to survive
Sweep	Hits everything around it; blinds and slows	Block with a shield
Slam	Smashes down along a red line and breaks shields	Step aside once the line locks
Phantom Sweep	Spins three times, then appears right behind you	Turn around and block
Earth Shock	Rises, dives, and sends a shockwave across the floor. Anyone thrown into the air is shot down by a beam	Leave the impact point, jump the wave
Prism	Three violet lasers that ricochet off pillars and walls, faster after every bounce	Block one head-on and it bounces back
Crescent	A swing, then the cut itself flies low across the floor	Jump it at the right moment
Resonance Orbs	Glowing homing orbs that can be batted back at the god	Hit them back with your sword
Summon	Abyssal Eyes that heal the god if left alone for 30 seconds	Destroy them early

Phase 2: the Split (from 50%)

Eight identical figures surround every player. Only one is real; a single hit shatters a clone. They fire formation lasers, make a chain dash (one after another, every half second), and perform an eightfold earth shock whose waves cross the floor. Then come turret clones on the pillars and a barrage from the sky.

The Final Form (after the killing blow)

The god you thought you killed rises again, crimson. It now fights at range:

four red eyes circling overhead that mark whoever they stare at
a maelstrom that drags in anyone it can see
judgement rays whose third shot breaks shields
floor-skimming beams
a heaven-strike after three bells
a resonance mark whose blast must be shared
searchlights that lift you helpless into the air before the god shoots you down
a God Warrior beam dragged across the floor in a cross, its trail erupting behind it
a laser rain from a sigil in the sky
and more

The Abyssal Catastrophe (once, at 25%)

Prelude → Starfall → Rifts → Phantom Cage (jump the low lasers, sneak under the high ones) → Ring of the End (a moving safe circle opens under each player) → The End (only the central altar is safe) → Exhaustion (5 seconds of 1.5× damage taken: your moment)

Rewards

Anti-Gravity Device. Keep it in your inventory. While gliding with an Elytra, right-click for unlimited abyssal boosts. One drops for every player who fought.
Abyssal Crystal. Left behind on the altar like the dragon’s egg; it can be mined and carried home. Hit it while holding an Anti-Gravity Device, and the device is drawn in: an Abyssal Ray hatches. The device or the Ray: the choice is yours.

Abyssal Ray

A manta-like creature that floats just above the ground, like its maker. Only the player who hatched it can ride it. It hatches in one of four looks, chosen at random: Sculk, End, Amethyst, or the rare Ancient (5%).

Space: a high leap. In the air it glides on its own.
Hold Space in mid-air: hang still for up to 2 seconds.
R (rebindable): blink up to 32 blocks to where you look. 3-second cooldown; rises at most 10 blocks.
Sneak + right-click: tell it to rest. It folds its wings and settles down.
Amethyst Shard: heals it.
It can carry you through the gate.

Items

Item	How to get it	Use
Warden Horn	Always dropped by the Warden	Abyssal Key ingredient
Abyssal Key	Recipe above	Opens an Ancient City gate. On an open gate’s frame it calls a rematch; on the portal itself it seals the gate
Echo Eye	Eye of Ender + Amethyst Shard + Bone	Flies towards the nearest Ancient City
Ancient Compass	Echo Eye + Compass	Needle points to the nearest Ancient City
Abyssal Drill	4 Iron Ingots, Observer, Piston, Furnace	Digs a shaft straight down to a set depth using a pickaxe and fuel. Hangs ladders as it goes (holds 512). Dug blocks are not kept
Anti-Gravity Device	Boss reward	Elytra boosts
Abyssal Crystal	Boss reward	Hatches an Abyssal Ray

Abyssal Drill recipe:

[Iron Ingot][Observer][Iron Ingot]
[Iron Ingot][Piston]  [Iron Ingot]
[Iron Ingot][Furnace] [Iron Ingot]

Requirements

Minecraft 1.21.1
Fabric Loader 0.19.5 or newer
Fabric API (for 1.21.1)
GeckoLib (Fabric, 1.21.1, version 4.9.3 or newer)

In multiplayer the mod is needed on every client and on the server.

FAQ

Can I play solo? Yes. Health scales with the number of players, so a solo fight is tuned for one — but it is still a hard fight.

What happens if we lose? As soon as no living player remains in the arena, the god heals fully and goes back to sleep. Approach it again to retry.

Can I fight it again after winning? Yes. Use a new Abyssal Key on the frame (reinforced deepslate) of the open gate and the god wakes again (the key is used up). The arena is rebuilt as new. Using a key on the portal itself seals the gate.

Languages?

Ancient Core: God of the Deep

介绍