Mortal Shell 2 Tarforge: How Upgrades Actually Work

The Tarforge is the machine in Marrow Keep that runs every weapon, sidearm and Tarstone upgrade in Mortal Shell II, and it does not come online by itself — you need to hand over four separate items to the NPC standing beside it and install a fifth through the machine’s own menu before it does anything useful. Coverage around the game’s launch window has flagged this as one of the easiest systems to half-miss, since the first unlock item sits in the prologue and the rest are scattered across dungeons you might skip. This guide walks through the unlock order, what each piece actually opens up, and where to put your first materials when you don’t have enough for everything.

The Tarforge is an important machine for you as well as Franz, as you can use it to upgrade your Mortal Shell 2 weapons, Tarstones, and Sidearms. Franz, the Tarforge Smith, is the character responsible for handling equipment upgrades, and you can find him at Marrow Keep, where he tends to the Tarforge. Marrow Keep itself is a location that serves as the central hub for your journey, so the Tarforge is effectively the one-stop equipment counter you’ll be returning to constantly. The reason it’s worth handling early rather than “eventually” is that the first unlock item is nearly impossible to skip, but the rest require detours most players wouldn’t take on their own.

You need five items to fully activate and upgrade the Tarforge, four of which need to be brought to Franz, while the last needs to be installed via an option in the Tarforge’s menu. The Muradean Actuator is the one you’ll almost certainly grab without trying — when you reach the Village Outskirts Beacon the game has you cleanse it, and on the way through you’ll spot a chest before the elevator with the Muradean Actuator inside. That single pickup is covered in more detail in a guide to the game’s opening hours if you want the full early-game route. The Obsidian Lathe is a proper detour: it comes from a dungeon called Martyr’s Tomb, due south of the Widow’s Overlook beacon in Fainweald, right next to the grave where you unlock the Tiel shell. Etching Needles sit past a boss fight — the item can be looted from a chest right before the Magdalena boss fight, near where you see Ruk past the bridge. The Foundry Stone and the fifth, menu-installed piece are the two least documented right now; early guides note their exact pickup routes are still being confirmed, so treat those two as a work in progress rather than a locked map.

This is where a lot of players trip up: giving Franz the Muradean Actuator unlocks main weapon enhancements, while giving him the Obsidian Lathe separately unlocks sidearm enhancements. These are not one shared upgrade track that opens with either item — they’re parallel branches, and each one only touches the weapon category it’s tied to. Put materials into the Muradean Actuator branch and your sidearm stays completely untouched until the Obsidian Lathe is handed over too. The reason the split matters ties directly into how stamina and combat resource costs work, which is covered separately in a breakdown of the game’s Resolve and Seals system.

To upgrade weapons and sidearms you need enough coins and smithing stones, with examples including Ventrium, Laterite, Dorsalite, Thoracium, and Ossinite. Ventrium shows up earliest and most often since it’s paired with Coin on both the Muradean Actuator and Obsidian Lathe branches. The other four stones scale differently depending on how deep into a weapon’s upgrade path you go — one community-run upgrade calculator lists noticeably higher totals of Ventrium, Laterite and Dorsalite than Thoracium or Ossinite across a full weapon path, which lines up with those last two being rarer, higher-tier drops rather than early-game filler.

Those figures come from a fan-run planner rather than an official patch note, so treat them as a rough shape of the curve rather than a guaranteed number — early guides are still mapping exactly where Dorsalite, Laterite and Ossinite drop most reliably.

Each level on the Tarforge does two things at once: it slightly increases damage, and separately lowers how much it costs you to actually use the weapon. Those are two different payoffs that matter at different points in a run — raw damage wins short, aggressive trades early on, while the reduced cost matters more once you’re grinding through longer fights where you’re swinging or firing repeatedly. Since your primary weapon via the Muradean Actuator is the one thing equipped in every single fight, that’s the branch that pays back fastest when materials are limited. The Obsidian Lathe branch is worth delaying until you’ve got Ventrium and Coin to spare, since sidearms supplement your kit rather than carrying it.

Full Tarstones progression is its own system with its own XP curve and gets a dedicated breakdown elsewhere — the short version is that once a Tarstone hits its second threshold, maxing it out costs six Tarcore instead of coin, which is a slower and separate grind from weapon upgrades.

Based on how the prologue and early campaign locations line up, collecting the Muradean Actuator, Obsidian Lathe and Etching Needles for a player heading straight for them without much detouring is realistic within roughly 6 – 10 hours, since the Actuator is essentially handed to you and the other two sit behind content most runs pass through anyway. That number is an estimate built from beta-era pacing rather than a confirmed launch figure, and it only covers getting the unlocks — actually funding every weapon and sidearm level with Ventrium, Laterite, Dorsalite, Thoracium and Ossinite is a much longer material grind that stretches across a full playthrough rather than a single sitting.

Myth: Killing Franz Locks You Out of Upgrades

It doesn’t. Franz can be killed without preventing the Tarforge from accepting the required items and unlocking the upgrades, so the machine keeps functioning either way — the only real question is whether losing him as a character is worth the extra crafting materials.

Myth: Obsidian Lathe Also Boosts Your Main Weapon

It doesn’t touch your primary weapon at all. The Muradean Actuator unlocks main weapon enhancements, and the Obsidian Lathe separately unlocks sidearm enhancements — treat them as two shopping lists, not one combined pool.

Myth: You Have to Rush All Five Items Immediately

You don’t need to have everything day one. The Muradean Actuator arrives almost automatically during the prologue, and the boss fights guarding Etching Needles and the Obsidian Lathe are the kind of content most runs clear naturally on the way through the map covered in the boss order guide — there’s no penalty for picking these up out of order.