TL;DR

The Tarforge is your main upgrade station in Mortal Shell 2, located in Marrow Keep next to an NPC named Franz.
You need 5 key items to fully unlock all Tarforge functions: Muradean Actuator, Obsidian Lathe, Etching Needles, Foundry Stone, and Endless Core.
The Muradean Actuator unlocks melee weapon upgrades — found in the prologue at Village Outskirts Beacon.
The Obsidian Lathe unlocks sidearm upgrades — found in Martyr’s Tomb dungeon, south of Widow’s Overlook.
The Etching Needles unlock Tarstone upgrades — found in the Glutted Mire dungeon just before the Magdalena boss fight.
The Foundry Stone unlocks weapon smelting — found near the Outskirts of Mammon Beacon.
The Endless Core removes all upgrade level caps — found late in the campaign in the Unfound Path dungeon.
Weapon upgrades cost Coins and smithing stones. Tarstone upgrades require XP earned by killing enemies, then Tarcore to max out.
[Updated – Balance Patch 1] Smelting at the Tarforge now costs 75% less Gloom. Enemy gold drops have been significantly increased, and enemies in Mammon now drop double gold.
[Updated – Week 1 Patch] Glimpses and Tarcores are no longer finite resources — you can fully upgrade all shells and Tarstones in a single playthrough. Fragile Tarstones are a new item class, and Mether’s Severance is a new shell respec item.

Table of Contents

Tarforge in Mortal Shell 2: Location, Upgrades & How to Use It

The Tarforge is the most important upgrade station in Mortal Shell 2. It is where you improve your weapons, sidearms, and Tarstones — and without it, your gear stagnates while enemy difficulty keeps climbing. But the Tarforge does not start out fully functional. You have to unlock each of its features one by one by finding and delivering key items spread across the world.

This guide covers where the Tarforge is, who runs it, all five unlock items and where to find them, what materials you need to upgrade, and how the Tarstone system works. Before you dive into upgrades, make sure you have a handle on
how to cleanse corruption in Mortal Shell 2 —
Beacons are your main source of the smithing materials and Gloom you need to fund upgrades. And if you are looking for what to upgrade first, our full
Mortal Shell 2 All Weapon and Sidearm Locations guide
shows every armament in the game.

Update notice: This guide has been updated to reflect Balance Patch 1 (August 20, 2026) and the Week 1 / First Major Patch (August 30, 2026). Key changes affect Tarforge smelting costs, the Tarcore and Glimpse economy, Tarstone behaviour, new items, and several weapons you may be upgrading. All relevant sections are marked inline.

Mortal Shell 2 is out on
Steam,
PlayStation, and
Xbox.
Visit the official Mortal Shell website for more.

Where Is the Tarforge in Mortal Shell 2?

The Tarforge is inside Marrow Keep — the central hub you unlock after completing the prologue. When you first arrive at Marrow Keep, take the path to the left from the main Beacon and head into the chamber nearby. You will find both the Tarforge and Franz standing next to it.

Franz is the NPC who manages the forge. When you first speak to him, he explains that the Tarforge is broken and needs specific parts to function properly. Your job throughout the game is to collect those parts and bring them back to him — each one unlocking a new upgrade category. [Week 1 Patch] Franz’s conversations have been fixed to trigger in the correct order, and he now returns to his crank after being interrupted, so early dialogue that was misfiring at launch should now play properly.

Note that Franz can actually be killed. Doing so provides extra crafting resources but does not disable the Tarforge — the machine itself still works and the items can still be installed. Most players will want to keep him alive for story reasons, but the choice is yours.

All 5 Tarforge Unlock Items and Where to Find Them

You need five specific items to fully activate the Tarforge. Four are brought to Franz directly. The fifth is installed through the Tarforge menu itself. Here is every item, what it does, and exactly where to find it.

1. Muradean Actuator — Unlocks Melee Weapon Upgrades

What it does: Activates the Tarforge and enables melee weapon enhancement. Without this, the forge cannot be used at all.

Where to find it: Inside a chest at the Village Outskirts Beacon during the prologue. This Beacon is part of the mandatory early route — you have to cleanse it to progress, and the chest with the Muradean Actuator is right inside. It is nearly impossible to miss. If you somehow bypassed it, you can fast travel back after unlocking Mether’s Breath.

When to deliver it: As soon as you arrive at Marrow Keep after the prologue. Give it to Franz immediately to start upgrading your melee weapon right away.

2. Obsidian Lathe — Unlocks Sidearm Upgrades

What it does: Expands the Tarforge to cover sidearm enhancement, letting you upgrade ranged weapons separately from melee.

Where to find it: Inside the Martyr’s Tomb dungeon in Fainweald. The dungeon is due south of the Widow’s Overlook Beacon — it sits right next to the grave where you find the Tiel shell. Fight through the dungeon and collect the Obsidian Lathe from inside. If you need to exit the room after grabbing it, shoot the device above the metal gate to open it.

There is also a Tarstone in the same mine, so be sure to check the area thoroughly before leaving.

3. Etching Needles — Unlocks Tarstone Upgrades

What it does: Enables leveling up Tarstones at the Tarforge, and also allows you to collect Tarcore — the resource needed to max Tarstones out to their final level.

Where to find it: Inside the Glutted Mire dungeon, which is the first Corrupted Gate dungeon in the southeast of Fainweald. Here is the route through the level:

Progress through normally until you tag the Sunken Village Beacon.
Cross the rope bridge and defeat the Tarblighted Shepherd boss and his demon-transforming sheep.
Squeeze through the gap in the wooden boards in the next area.
You will see Ruk perched nearby warning you about the upcoming major boss.
The chest with the Etching Needles is just past Ruk’s position, before the Magdalena boss arena entrance.

Do not go into the boss fight without picking up this chest first. It is easy to rush past in the excitement of reaching a major encounter.

4. Foundry Stone — Unlocks Weapon Smelting

What it does: Adds the smelting function to the Tarforge. Smelting reverts a weapon or sidearm back to its base, unleveled state — but it also refunds all the upgrade materials you spent on it. This is useful when you want to swap investments from one weapon to another without losing resources permanently. [Balance Patch 1] Smelting now costs 75% less Gloom than at launch, making it a much more practical option for adjusting your build mid-campaign.

Where to find it: In the Ruins of Mammon, near the Outskirts of Mammon Beacon. Fast travel there and look for a chest in the blasted, open area near the gateway. A dozen knights and soldiers are guarding the area, so either fight through them or time your grab carefully and run.

5. Endless Core — Removes All Upgrade Level Caps

What it does: Lifts the existing upgrade ceiling on all weapons and sidearms, letting you push them to their maximum potential. This is a late-game item and the last thing you will unlock for the Tarforge.

Where to find it: Deep inside the Unfound Path — the game’s final major dungeon, which unlocks after defeating at least 5 of the 6 Corrupted Gate bosses. Here is the exact path:

Progress through the Unfound Path normally until you clear all the corrupted tendrils blocking the route.
This reveals a Beacon called the Hidden Nave, located in the middle of the zone just before the final boss.
Inside the Hidden Nave, find the first bonfire and then run to the other side of the tunnel to find a second bonfire.
Return to the first bonfire — a torch will have appeared there.
Pick up the torch and walk through the fog. A hidden area will reveal itself.
Follow the sloping path all the way to the bottom. The chest at the end contains the Endless Core.
There are also several gloom-filled chests along the way — interact with the doorway first before looting them, as it requires you to offer up all your current Gloom.

Unlike the other four items, the Endless Core is installed directly through the Tarforge menu rather than handed to Franz.

How to Upgrade Weapons and Sidearms at the Tarforge

Once you have delivered the Muradean Actuator (and later the Obsidian Lathe) to Franz, you can begin enhancing your weapons and sidearms at any time by visiting the Tarforge in Marrow Keep.

Each upgrade costs two things: Coins and smithing stones. The smithing stones are materials with specific names that correspond to different upgrade tiers:

Ventrium — used for lower-tier upgrades (levels +1 to +5)
Laterite — used for mid-tier upgrades (levels +6 to +10)
Dorsalite — used for higher-tier upgrades (levels +11 to +15)
Thoracium — used for near-cap upgrades (levels +16 to +20)
Ossinite — used for the final upgrade levels, unlocked with the Endless Core

These materials are found throughout Fainweald and the Ruins of Mammon — inside chests, dropped by enemies, looted from dungeon rooms, and occasionally found near Beacon areas after cleansing. Ventrium is the most common and easiest to collect in the early game. The higher-tier materials become available as you push deeper into the world. [Balance Patch 1] Enemy gold drops have been significantly increased across the board, and enemies in Mammon now drop double gold, so building up Coins for upgrades is faster than at launch.

The upgrade investment is permanent unless you use the smelting function (after finding the Foundry Stone), which refunds all spent materials at the cost of resetting the weapon to base level. [Balance Patch 1] Smelting now costs 75% less Gloom, so don’t be afraid to use it when switching your build focus.

How to Upgrade Tarstones at the Tarforge

Tarstone upgrades work on a completely separate system from weapons — and they require a bit of patience. Here is how the full process works.

[Week 1 Patch — Important Economy Change] Glimpses and Tarcores are no longer finite resources. You can now fully upgrade all shells and all Tarstones within a single playthrough. Merrick also now sells Tarcores and will restock them as you progress. If you leveled up Tarstones before this patch, you will find a compensatory cache of Tarcores in your inventory automatically. Tarstones also now yield more Tarcores when broken than they did at launch.

Step 1 — Equip a Tarstone and Kill Enemies

Tarstones only gain XP when they are slotted into your currently equipped weapon or sidearm. You must have the Tarstone equipped while fighting — Tarstones sitting in your inventory do nothing. Kill enemies as normal and the Tarstone passively accumulates experience for every enemy defeated. [Week 1 Patch] A bug where Tarstones continued to gather experience after reaching maximum level has been fixed, along with missing tooltips on a number of Tarstones.

Step 2 — Level 1 to Level 2 at the Tarforge

When a Tarstone reaches 10,000 XP, return to the Tarforge. Leveling it from 1 to 2 costs 100 Coins. This is cheap and fast. Doing so also grants you 1 Tarcore — a special resource used in the next step.

Step 3 — Level 2 to Max Using Tarcore

Once a Tarstone hits 20,000 XP, you can upgrade it to its maximum level. This final upgrade requires 6 Tarcore. [Week 1 Patch] Tarcores are no longer a finite resource and can be purchased from Merrick, which removes the previous pressure to grind XP on multiple throwaway Tarstones just to generate enough Tarcore. Focus on the Tarstones you actually want to use.

Fragile Tarstones (New — Week 1 Patch)

[Week 1 Patch] A new class of Tarstone called Fragile Tarstones has been added to the game. These break after losing durability, and when they break they yield a Tarcore. Two existing Tarstones — the Justicar’s Stone and the Gloombound Stone — have been converted to Fragile variants, with increased passive effects and added on-break bonuses. Existing copies in your inventory are automatically converted. Fragile Tarstones can be found multiple times per playthrough, are sold by Merrick, and drop from certain enemies and dungeons. Two new Fragile Tarstones have also been added: the Glimpse Stone (wears down as you defeat enemies, then breaks into Glimpses) and Egon’s Stone (revives you at a dungeon’s entrance when you die inside, and spares your Gloom on its final break).

Mether’s Severance — Shell Respec (New — Week 1 Patch)

[Week 1 Patch] A new shell respec item, Mether’s Severance, has been added to the game. Hand it to Zhirelle, the shell keeper, and she will sever your bond with a Shell — resetting it entirely and refunding all Glimpses you spent on it. This item can be purchased from Merrick and will restock as you progress. If you have ever regretted your shell upgrade path, this is now your way out.

What Are the Best Things to Upgrade First at the Tarforge?

With limited materials early on, it helps to know what gives the biggest return.

Melee weapon first. You use your primary weapon constantly — it generates your Resolve, deals most of your damage, and shapes every combat encounter. Upgrading your main weapon even by a few levels makes a noticeable difference against tougher enemies. Focus here before sidearms.

Your main sidearm second. Once the Obsidian Lathe is in, start putting a few upgrades into whichever sidearm you use most. The Naylshotte and Forgotten Crossbow are popular early options. Do not spread resources too thin across multiple sidearms. [Balance Patch 1] The Caged Hystrix and Triarch Repeater no longer require a minimum amount of Resolve to fire, making them more viable from the moment you pick them up.

The Axe & Dagger is worth the investment. If you have it from the Shrine of Trials (the dungeon unlocked with the Chapel Key), it is one of the most versatile early weapons and scales well through upgrades. It pairs especially well with Tiel.

Prioritise the Axatana late — and note its buff. Many players consider the Axatana the best overall weapon in the game. Once you reach the Ruins of Mammon and collect it, funnel your remaining upgrade materials here. [Week 1 Patch] The Axatana received a significant improvement: its weapon ability now grants invulnerability frames and inflicts Fragile stacks, and its combat Tarstone active triggers correctly. It is even stronger than it was at launch.

Obsidian Hammer and Great Martyr’s Blade are now worth considering. [Week 1 Patch] The Obsidian Hammer received a full balance pass and now hits substantially harder. The Great Martyr’s Blade also deals more damage after a fix that prevented its previous buff from applying. [Balance Patch 1] The Troubadour’s Lute saw a 100% attack damage increase and the Great Martyr’s Blade received a 20% damage boost in that same patch, so both weapons are stronger than launch players may remember.

For Tarstones, start leveling early but don’t stress about Tarcore. [Week 1 Patch] With Tarcores now purchasable from Merrick and no longer finite, the old pressure to rush multiple Tarstones to tier 2 just to bank Tarcore is gone. Still equip Tarstones while you fight — passive XP gain costs you nothing — but you no longer need to sacrifice your preferred build just to generate resources.

Tips for Getting the Most Out of the Tarforge

Grab the Muradean Actuator before leaving the prologue area. You cannot miss it if you cleanse the Village Outskirts Beacon — but make a mental note so you deliver it to Franz the moment you reach Marrow Keep.
Collect Ventrium from every dungeon and chest you can. It is the most commonly needed smithing material in the early and mid-game. Running out of it stalls your upgrades fast.
Use smelting freely. [Balance Patch 1] Smelting now costs 75% less Gloom than at launch. Resetting a weapon to switch your build focus is no longer a significant sacrifice — use it whenever it makes sense.
Buy Tarcores from Merrick. [Week 1 Patch] Tarcores are now available for purchase and restock over time. You no longer need to grind multiple Tarstones purely to generate them. Spend Coins at Merrick to cap your preferred Tarstones faster.
Check Merrick’s stock regularly. [Week 1 Patch] Merrick’s inventory has expanded significantly. He now stocks Glimpse Stones, Egon’s Stones, Tarcores, and Mether’s Severance — restocking as you progress. Visit him after major milestones.
Pick up Egon’s Stone for dungeon runs. [Week 1 Patch] This new Fragile Tarstone revives you at a dungeon’s entrance when you die inside and spares your Gloom on its final break — a significant quality-of-life improvement for difficult dungeons.
The Endless Core is worth pursuing before the final boss. If you plan to push the difficulty ceiling, get the Endless Core from the Hidden Nave before engaging the final encounter — it opens up significantly stronger weapon builds for the late game.
Franz can be killed for extra materials. If you are resource-starved, this is a valid option. The Tarforge still functions fully without him.
Dungeon reward chests have been revised. [Week 1 Patch] Reward placement across the first two regions and Mammon has been updated, and some missing arena dungeon rewards have been restored. If you cleared dungeons at launch and felt shortchanged on loot, some chests may have been reset or restocked.

Wrapping Up

The Tarforge is not something you activate once and forget. It is a system that grows with you — unlocking new features as you explore, requiring consistent investment in materials, and rewarding players who engage with it throughout the whole campaign rather than saving upgrades for the end. With the Week 1 Patch, the economy around Tarcore and Glimpses has been substantially loosened, smelting is much cheaper, and new items like Fragile Tarstones and Mether’s Severance give you more flexibility than ever before.

Get the Muradean Actuator to Franz early, start upgrading your melee weapon, pick up the Obsidian Lathe from Martyr’s Tomb, and make sure you grab the Etching Needles before you walk into the Magdalena boss fight. Check Merrick’s stock regularly after the Week 1 Patch — his inventory is now much more useful. The rest unlocks naturally as you push through Mammon and into the final dungeon. For more on navigating the world that supplies all these materials and weapons, read our
Mortal Shell 2 Beginner’s Guide
and our full
Mortal Shell 2 Review.