Mortal Shell 2: How to Upgrade Weapons Beyond Max Level With the Endless Core

Weapons and sidearms in Mortal Shell 2 hit a hard ceiling at level 16 until you find the Endless Core. This single item removes that cap at the Tarforge, letting you push your favorite armaments past +16 as long as you have the smithing stones and coins to pay for it.

Quick answer: Grab the Endless Core from the Hidden Nave beacon inside the Unfound Path (the game’s final major dungeon), return to the Tarforge in Marrow Keep, and choose Install Endless Core. After that, the Enhance Weapons menu will let you upgrade past level 16 using Thoracon and coins.

What you need to break the weapon level cap

The Endless Core is a late-game pickup, so it becomes available only once you reach the closing stretch of the campaign. It is the last of the five Tarforge items, and unlike the others it is not handed to Franz. Instead, you install it directly through the Tarforge menu.

Requirement	Detail
Item	Endless Core
Location	Hidden Nave beacon, inside the Unfound Path (final major dungeon)
Install point	Tarforge in Marrow Keep
Effect	Removes the level cap on all weapon and sidearm upgrades
Upgrade cost	Thoracon and coins per level past +16

Where to find the Endless Core in the Unfound Path

Progress through the Unfound Path and clear out all of the corrupted tendrils in the zone. Doing this unlocks the Hidden Nave beacon, which sits in the middle of the area right before the final boss.

Interact with the Hidden Nave beacon and select Enter Beacon. Inside, you will find your first bonfire in the tunnel.

Run to the far side of the tunnel until you reach a second bonfire, then head back to the first one. A torch will have appeared there. Pick it up.

Carry the torch through the fog. The light reveals a hidden path that leads into an entirely different area of red-lit caves and ledges.

Follow the sloping path downward, dropping off the ledges until you reach the bottom. Loot the chest at the stone altar there to claim the Endless Core.

Note: There are extra chests holding gloom nearby, but interact with the doorway first, since it asks you to offer up all the gloom you are carrying. Do that before you loot the surrounding resources so you can grab everything without losing it.

Install the Endless Core at the Tarforge

Fast travel back to Marrow Keep and walk to the Tarforge where Franz works.

Open the Tarforge menu and choose Install Endless Core. This is a Tarforge option, not something you hand to Franz.

Open the Enhance Weapons menu and select any weapon or sidearm sitting at +16. You will now see the option to push it to +17 and beyond, spending Thoracon and coins for each level.

How to confirm the cap is gone

You know it worked when the Enhance Weapons screen shows an upgrade path past level 16, for example the LEVEL +16 → +17 prompt on a weapon like the Axatana. If the option is still greyed out at +16, the Endless Core has not been installed yet. Return to the Tarforge menu and select Install Endless Core before trying again.

Because the Core lifts the cap on every armament, you only need to install it once. From then on, the limit on higher-level upgrades comes down to how much Thoracon and how many coins you can stockpile, so spend those materials on the weapons and sidearms you actually rely on in combat.