How to Unlock Ergo Sum - Destiny 2 Guide - IGN (2024)

Ergo Sum is a unique, new Exotic sword in Destiny 2: The Final Shape. Unlike most other Exotic weapons, it is capable of dropping with different elemental affinities, frames, perks, and traits. As there are so many different roll possibilities for the weapon, Ergo Sum can also be farmed several times each week after you initially get it. Here is how to unlock Ergo Sum for the first time, as well as how you can get it to drop with different rolls.

SPOILER WARNING: This quest takes place after the main missions within The Final Shape's campaign. Therefore, there will be spoilers below.

Unlocking Ergo Sum in Destiny 2 requires you to...

• Complete The Final Shape's campaign and talk to your Ghost
• Complete Queens Part 1
• Complete Lost in the Light quest
• Complete Found in the Dark quest
• Complete Queens Part 2

You can also skip ahead to the section at the bottom of this guide on farming Ergo Sum.

Destined Heroes Exotic Quest

Destined Heroes is the exotic quest for Ergo Sum. It can be picked up after weakening The Witness in the final campaign mission, Iconoclasm. Firstly, you will need to head to the Old Tower in The Pale Heart and talk to your Ghost to pick up the quest. You can then interact with the radio just by them to complete the next step.

After listening to the radio signal, you can begin the Queens Part 1 adventure, which is just next to the tower balcony in the Old Tower. This is a pretty simple adventure, although it will challenge you with some light puzzles, similar to the ones in the main The Final Shape campaign.

Queens Part 1

At the start of the mission, you will need to head to the war table room within the Old Tower and observe what the Lucent Hive and Savathun are up to. Continue down the tower from this room and kill the Hive Knight to pick up the Sword relic. The relic allows you to fire a projectile and reflect damage when shot at. Both of these mechanics you will need to get a hang of to complete this mission, as you will need to hit some orbs with the projectile and reflect enemy damage so that their shots hit the right elemental rune.

To open the first gate, reflect the Acolyte's shots and aim at the rune to overload it with Void energy.

You will then need to repeat this for the nine other runes in the next area, matching the elemental types. To the left, you want to reflect the Knight's damage and aim at the Solar runes. On the right, reflect the Shrieker's Void damage and hit the Void runes around it. Then, directly opposite where you entered, you can find some Wizards. Reflect their damage and hit the Arc runes.

With each rune set you overload, you will drop the shields of the corresponding enemy and be able to kill them with your weapons or the Sword's projectile.

For the rest of the mission you will just need to repeat this at the next ritual sites. The only difference is that if the Runes are enshrouded in a green Hive barrier, you will need to hit the orbs near them to destroy the barrier before you can reflect the damage and drop the shields of your enemy. The third and fourth ritual sites will have you pick up balls of Arc, Void, or Solar energy and throw it at the runes, instead of reflecting the damage.

Once you have completed the fourth rune, the mission will wrap up before you can kill Savathun, and you will be able to continue the exotic quest.

With the quest complete, you will need to go back to the war table room in the Old Tower and speak with Micah at Micah's Conduit. They will give you a completely different quest, which you can complete - earning yourself a Legendary The Final Shape weapon. But, you don't need to finish it to get Ergo Sum.

So, after speaking with Micah, you will then need to talk to Cayde back outside, before speaking to your Ghost once again. When speaking with your Ghost, under the Transcendance items, you can start two more quests: Lost in the Light and Found in the Dark. Both of these need to be completed to continue Destined Heroes.

Lost in the Light

Both Lost in the Light and Found in the Dark are rather linear and easy to complete. They just take a bit of time, as you will need to finish a couple of adventures for each quest.

To begin Lost in the Light, head to The Landing area in The Pale Heart and follow the objective marker into the cave, where you will find one of the Witness' Darkness areas where he has replicated memories from you and your allies. In here, you will find a Manifestation of the Light — a Prismatic chest. Opening it will give you either a Super, melee attack, grenade, or Aspect for your Prismatic subclass.

The next step is to complete the adventure The Hollow Part 1. This is a brief adventure that leads into the final steps of the quest. The beacon to start it spawns right next to the chest you just opened.

The Hollow Part 1

In this mission, you will team up with Mithrax and need to slay a ton of Fallen. In this first room, simply defend your ghost and kill as many Fallen as possible while they hack the systems.

Once it has done this, you can head back out of the cave and into The Blooming area. Here, you will find a huge barrier which has been erected by House Salvation. To destroy it you will need to head back the way you came and climb up a small cliff. Follow the objective marker down this path and you will come across another group of enemies. Your objective will also change to "Destroy Shield Generators".

This is another small mechanic introduced in this mission, and The Hollow, Part II later on in this questline. By killing the Taken Captains, you will be able to be pick up Motes of Light or Motes of Darkness that they drop. When you have 5 Motes of the same type you can dunk it into the opposite type's plate in the area. So, with Five Motes of Light from the Captains named "Eater of Light", you can dunk them into the Darkness plate in the cave just ahead.

Then, in the cave you can kill the Captains called "Eater of Darkness" and grab 5 Motes of Darkness to dunk in the Light plate back outside. Doing this for each plate will destroy the generators, allowing you to return to the barrier, which will now be lowered.

Back at the barrier, Korha The Hollow from House Salvation will spawn. This Captain is nothing special and can be taken down pretty quickly. However, at 50% health Korha will spawn a shield. This can be removed by doing the exact same thing you just did:

• Kill the two Eater of Light Captains
• Dunk 5 Motes into the Darkness plate
• Kill the two Eater of Darkness Captains
• Dunk 5 motes into the Light plate to remove the shield.

Once the fight ends, you will complete the mission and be teleported back to The Witness' Darkness area to find another Manifestation of the Light, granting you another Prismatic Super, grenade, melee ability, or Aspect.

After opening that chest, you can then move onto The Hollow Part 2 mission.

The Hollow Part 2

The beacon will spawn next to you once again, allowing you to jump right in. This mission takes you to Europa to chase down Korha. This mission is even simpler in terms of mechanics.

Simply follow the path forward and throughout the mission you will need to summon an Exploder Shank to destroy the door blocking your way. However, you will need to protect it by killing the enemies trying to destroy it before it reaches its destination. When it reaches its destination, you can shoot it to blow up the door.

Do this a few times and kill the enemies in-between these sections. When prompted to defeat Weaver Squads, kill the Servitors and deposit the Arc charges into the generators. This will spawn a group of Shanks that will destroy the shields protecting the Weavers.

Before long, you will end up fighting Korha. As with the first part of this adventure, simply repeat the mechanics from earlier in the mission:

• Kill the Servitors
• Load the arc charges to remove the shield
• Wittle Korha's health down until the fight finishes

You will then be teleported back to the Darkness cave, where you can open one more chest and complete this quest.

Found in the Dark

With Lost in the Light completed, you can now complete Found In The Dark. Structurally, this quest is exactly the same. To kick things off, land in The Blooming area on The Pale Heart and make your way to The Seclusion. Here you will find another Prismatic Chest to open in the Darkness cave. Just by it, the Home Part 1 adventure will spawn, which you need to complete next.

Home Part 1

A little way into the mission, upon reaching your first objective, you will need to find an Artillery Antenna to destroy some generator shields. These are held by Artillery Officers in the area, who will drop them upon being killed. With the antenna, head over to the generator and place it to destroy the generator. Repeat this once again to destroy the second one.

From there, continue on until you need to destroy the generator shields once again. However, this time, you will need to remove the barrier protecting them by killing the two Psions in a bubble. Once these are down, you can kill the Artillery Officers and destroy them with the antennas.

Doing this will spawn the Artillery Commander. This is a regular Colossus and shouldn't pose too much of a threat. The other enemies are the ones you want to watch out for. There are so many of them that it can be easy to get overwhelmed, although Caiatl's forces will help somewhat.

At 50% health, the Artillery Commander will get a shield, which can be removed by killing the Bound Omen enemies. These powerful Weavers will require you to use Transcendence to be able to damage them.

Once you have killed them, though, you can finish off the Cabal forces and complete the mission. From there, you will be taken back to The Witness' Darkness cave and get another Prismatic subclass reward. Opening the chest will then spawn the Home Part 2 adventure, which you need to finish.

Home Part 2

For the most part, this adventure is almost identical to Part I in terms of mechanics. Within The Divide, simply kill the Psions to lower the barriers on the generators and then destory them. However, you will be using charges of Unstable Light from Centurions nearby, instead of the antennas.

After killing the Centurion, you simply pick up the charge and throw it at the generator to destroy it. Repeat this three times through the mission, and then you will complete it. Besides that change, just be sure to stand next to the fire pits at least once every 45 seconds to avoid freezing to death.

Also, when facing off against the Goliath Tank at the end of the mission, you will need to repeat this a couple of times, as it will restore its shield when it reaches 50% health and just before it dies. This fight can be tricky due to the sheer number of enemies, but a weapon like a Sniper Rifle or Linear Fusion Rifle can target the legs of the Goliath Tank easily from afar.

With that adventure complete, you will return to the cave and grab the final Prismatic Chest.

Additionally, with both Lost in the Light and Found in the Dark complete, you can continue with the main Exotic quest, Destined Heroes.

Queens Part 2

The final stage of this extremely long quest is to complete the adventure Queens Part 2, which is found back at the Old Tower. Upon starting it, you will continue forward until you need to acquire a bunch of Taken Energy from killing Taken. This isn't too tricky, but just watch out for the huge pit of Ogres in the middle of the area.

When you have all the Taken Energy you need, jump across the Taken platforms that spawn nearby. Collect the Taken Energy again a little later when prompted, and then when your screen turns black and white, you will want to interact with the three light fissures in the ground — all of which are marked in-game.

Do this a second time and kill the Tormentors that spawn. Once defeated, you will finish the adventure and finally be at the end of your quest to get Ergo Sum.

The last step is to talk to your Ghost at the Old Tower and pick up the Dyadic Prism. This will allow you to return to The Sacarium on the far eastern edge of The Pale Heart, where you fought The Witness. Once here, interact with the veiled statue to get Ergo Sum

For more on Destiny 2: The Final Shape, check out these guides next:

• The Best Final Shape Builds
• Pathfinder Progression System Details and Guide
• Destiny 2 The Final Shape Weapon Tuning Details
• Destiny 2 The Final Shape Exotic Class Item Perks Details