Duality Guide – Complete Destiny 2 Dungeon Walkthrough

Introduction

The Duality dungeon was released in Destiny 2 during Season of the Haunted. The guide will take you through every step needed to complete it, covering all mechanics, strategies, and loadouts.

Table of Contents

In this guide, we will cover the following subjects:

• Dungeon Preparation
• How to access the dungeon
• First Encounter
• Second Encounter
• Boss Encounter
• Loot Table
• Extras & Challenges
• FAQ
• Conclusion

How to access the dungeon

To access the Duality dungeon, you need to have the Witch Queen Dungeon Key purchased on your account.

You must open the destination menu and launch the activity from the Derelict Leviathan node on the Moon.

Dungeon Preparation

Duality dungeon features unique mechanics, so being prepared with the best meta loadouts will help you out immensely during each encounter. I’ll be going over some of the best weapons & subclasses that you should be using to ensure your success.

Best subclasses & builds

Getting started

Once you’ve obtained the quest, navigate to the Moon and locate the dungeon marker in the Derelict Leviathan area.

Best weapons loadouts

Here, I’ll be going over some of the best meta weapons to use in the Duality dungeon:

Reaching the first encounter

To reach the first encounter in the Duality dungeon, fight through the Leviathan’s corridors and use the Bell of Conquest to shift into the Nightmare realm. Navigate a short jumping puzzle and switch between realms to clear enemies and unlock doors. After progressing through this section, you’ll drop into the arena where Nightmare of Gahlran, Sorrow Bearer awaits.

First encounter

General Objective Overview

In the first encounter of Duality, your fireteam must collect and deposit two Standards to trigger a DPS phase against Nightmare of Gahlran. To collect Standards, you’ll enter the Nightmare realm via a central bell, defeat Standard Bearers in their chambers, and return to the normal realm to dunk them. The encounter revolves around efficient realm transitions, Standard collection, and plate-based boss damage.

Arena & Layout

The encounter takes place in a circular arena with four Standard plates positioned at the edges and a large bell in the center. Each side of the arena features doors that lead to Nightmare chambers where Standard Bearers reside. Bellkeepers spawn in both realms to gate your transitions.

Team Roles & Asignments

Mechanics

Use the central bell to enter the Nightmare realm, where each marked door leads to a Standard Bearer encounter. Defeat these enemies to claim a Standard. Bellkeepers must be cleared to enable return transitions. Once both Standards are dunked in the matching plates, Gahlran becomes vulnerable and enters the DPS phase.

DPS Phase

Gahlran spawns in the middle and rotates between plate positions. He becomes vulnerable at each plate for a short time, allowing your fireteam to deal damage before he teleports. After visiting all active plates, the DPS phase ends, and the cycle resets.

Tips & Mistakes to Avoid

✔️ - Assign roles early: Everyone should know who’s running, who’s timing bells, and who’s clearing.

✔️ - Clear Bellkeepers immediately: You can’t transition realms without taking them down.

❌ - Don’t stand outside the bell range: You'll die if not near the bell during a realm transition.

❌ - Avoid depositing mismatched Standards: It resets DPS progress and wastes time.

Reaching the second encounter

After defeating Gahlran, shoot the nearby bell to enter the Nightmare realm and follow the newly opened path. You'll enter a winding crypt filled with tight hallways, pressure plates, and more bell-based puzzles. Use bells to shift between realms, avoid traps, and fight through waves of Cabal and Nightmare enemies. Continue progressing by unlocking doors using realm mechanics until you reach the next major arena, this is where the Vault encounter begins.

Second Encounter

General Objective Overview

In the second encounter of Duality, your fireteam must unlock three doors in a vault by collecting and depositing Standards that match specific symbols. This encounter focuses on identifying correct symbols, shifting between realms to retrieve matching Standards, and dealing with Bellkeepers and mini-bosses while managing wave-based combat.

Arena & Layout

The encounter takes place in a circular vault chamber with three large locked doors, each with an upper symbol display and a dunk plate below it. A bell sits in the center, used to shift realms, and two Symbol Pillars nearby display the active symbols required to unlock each door. Enemy waves spawn consistently in both the normal and Nightmare realms.

Team Roles & Asignments

Mechanics

DPS Phase

After the third door is unlocked, three mini-bosses become active, one at each vault door. The fireteam must defeat all three quickly to complete the encounter. These mini-bosses can be dealt with one at a time or simultaneously depending on strategy and firepower.

Tips & Mistakes to Avoid

✔️ - Assign a clear symbol reader: Quick and accurate callouts keep the run smooth.

✔️ - Kill Bellkeepers fast: Realm transitions are time-sensitive and essential for success.

❌ - Don’t collect the wrong Standard: Killing the wrong Standard Bearer wastes time and adds pressure.

❌ - Avoid realm desync: All players must be in bell range when transitioning, or left-behinds will die.

Reaching the boss encounter

After completing the Vault encounter and defeating the three mini-bosses, a new path opens behind the final unlocked vault door. Head through the hallway and prepare for a series of traversal and realm-shift puzzles. You’ll face waves of Cabal enemies, Bellkeepers, and pressure plates that require careful timing between realm transitions.

Use the central bells strategically to open gates and clear obstacles as you progress deeper into the Leviathan’s mindscape. After navigating the final jump section and clearing the last wave of enemies, you’ll arrive at the final arena where Nightmare of Caiatl, Princess-Imperial awaits.

Boss Encounter

General Objective Overview

In the final encounter of Duality, your fireteam must collect Standards to start the damage phase, manage realm transitions using the bell mechanic, and time your stuns to interrupt Caiatl’s movement. The fight is a mix of add-clear, bell coordination, and burst DPS.

Arena & Layout

The arena is a long rectangular hallway with three Standard plates on one end and a bell in the center. Caiatl starts at the far end and slowly moves toward the bell during DPS phases. Bellkeepers spawn in fixed positions during each damage cycle and must be dealt with quickly.

Team Roles & Asignments

Mechanics

DPS Phase

Once Caiatl starts walking, stun her by activating the bell when she is near. This gives a short damage phase at her position. After a few seconds, she teleports forward and continues walking. Repeat the bell stun up to three times per phase. If she reaches the bell without being stunned, it wipes the team.

Tips & Mistakes to Avoid

✔️ - Use burst DPS weapons like rockets or Linears for each short damage window.

✔️ - Kill Bellkeepers fast to ensure the next bell can be activated in time.

❌ - Don’t mistime the bell ring, if she’s not close enough, she won’t be stunned.

❌ - Avoid splitting up, all players must be near the bell during transitions or they'll die.

Loot Table

Here we'll be showing you every piece of loot you can acquire from the dungeon. Duality features 6 legendary weapons, 1 exotic, 1 normal armour set & 1 artifice armour set. Below you will find a list with all the weapons & armour pieces:

Nightmare of Gahlran (1st Encounter)	Unlock the Vault (2nd Encounter)	Nightmare of Caiatl (Final Encounter)
Lingering Dread Grenade Launcher Stasis |	Stormchaser Linear Fusion Rifle Arc |	Heartshadow Sword Void |
The Epicurean Fusion Rifle Void |	Unforgiven Submachine Gun Void |	New Purpose Pulse Rifle Stasis |
		Stormchaser Linear Fusion Rifle Arc |
		Fixed Odds Machine Gun Solar |
		Unforgiven Submachine Gun Void |
		The Epicurean Fusion Rifle Void |
		Lingering Dread Grenade Launcher Stasis |
Deep Explorer Helmet	Deep Explorer Gauntlets	Deep Explorer Gauntlets
Deep Explorer Gauntlets	Deep Explorer Plate	Deep Explorer Plate
Deep Explorer Greaves	Deep Explorer Mark	Deep Explorer Greaves
		Deep Explorer Helmet
		Deep Explorer Mark

These are all the possible loot that can drop from each encounter in Duality dungeon.

Extras & Challenges

Like in the previous dungeons, Duality also has a certain number of collectables, a title (or seal), solo & flawless triumph that awards a unique emblem & special badge on your dungeon report. We’ll be going over each of them and tell you what are the best tips & tricks on acquiring them.

Ship

The exotic ship is called Mandate of Strength, and you can acquire it by completing the Duality triumph, which requires full completion of the Duality dungeon on master difficulty.

Emblems

The Deepest Truth - Complete the "Duality" dungeon.

Untouched by Opulence - Complete all encounters in the "Duality" dungeon solo without dying and without leaving the activity.

Catalyst

After unlocking Heartshadow, you’ll need to head back into the dungeon for an extra challenge. This time, special Nightmare enemies will appear in specific spots, but only in the Nightmare realm. Taking them down will drop a flag, which you need to grab and place at the right plate nearby. Just be quick and make sure you exit the Nightmare realm before the timer runs out. Do this three times, and once the final flag is placed, a chest will appear, rewarding you with the catalyst.

For a comprehensive guide on how to obtain the catalyst for this weapon, be sure to watch the video above, where all the steps are explained in detail.

SKIP THE GRIND BUY DUALITY EXOTIC!

Master Difficulty

The Duality dungeon has normal & master difficulties to choose from. Completing the dungeon on master difficulty is required to complete the Discerptor title (seal). There are certain modifiers that makes the Master difficulty hard to complete:

Shielded Foes – You will face combatants with different elemental shields, like Arc, Void, etc.

Champion Foes – You will be facing Unstoppable, Overload and Anti-Barrier champions.

Master Modifier – Extra champions, extra shields, and your maximum effective power level is capped at 2030.

Surges – 25% bonus to a specific elemental damage.

Title & Seal

The title for the Duality is called Discerptor. Below you will find the list with all the required triumphs needed to acquire your seal:

Thoughtstealer - Complete the "Duality" dungeon.

Solo Thoughtstealer - Complete all encounters in the "Duality" dungeon solo.

Master Thoughtstealer - Complete the "Duality" dungeon on Master difficulty.

Mind Heist - Steal Calus's repressed memories.

Assassin's Lament - Earn the Exotic Sword Heartshadow.

United in Secrecy - Complete all encounters in the "Duality" dungeon with a full fireteam of clanmates.

Arc Fireteam Completion - Complete all encounters in the "Duality" dungeon with a full fireteam of Arc subclasses.

Solar Fireteam Completion - Complete all encounters in the "Duality" dungeon with a full fireteam of Solar subclasses.

Void Fireteam Completion - Complete all encounters in the "Duality" dungeon with a full fireteam of Void subclasses.

United in Class - Complete all encounters in the "Duality" dungeon with a full fireteam of the same class.

After you complete all 10 triumphs, the seal will be unlocked so you can equip it on all your guardians.

SKIP THE GRIND BUY DUALITY TITLE & SEAL!