You're wandering through the jagged, shadow-drenched ruins of the Land of Shadow, and you find a stone sheath. It looks like junk. It feels like junk. But it’s actually the starting point for one of the most convoluted weapon transformations FromSoftware has ever cooked up. The Sword of Darkness isn't just a weapon you pick up off a corpse; it’s a commitment.
Most players stumble onto the Stone-Sheathed Sword and think they’ve found a finished product. They haven't. Honestly, it’s basically a paperweight until you find the right altars.
The Shadow of the Erdtree DLC loves these weird, multi-step puzzles that force you to backtrack through some of the most annoying environments in the game. If you want a straight sword that scales with Faith and looks like it was forged in the deepest pits of a nightmare, this is your gear. But getting it? That’s a whole different story.
The Problem with the Stone-Sheathed Sword
Before you can even look at the Sword of Darkness, you need the base. The Stone-Sheathed Sword is found in one of three locations, but most people grab it at the Fog Rift Catacombs. You’ve got to ride a specific spike ceiling trap up to a hidden balcony. It’s classic Miyazaki.
The sword starts out... okay. It’s got a generic moveset. It doesn't do much. The real magic happens when you realize this thing is a shapeshifter. You can turn it into the Sword of Light or the Sword of Darkness.
But here’s the kicker: if you choose darkness, you’re trading away the holy radiance for something much grittier. You can swap back and forth, but you have to find specific altars scattered across the map to do it. It’s a bit of a trek every time you change your mind.
Finding the Altar of Darkness
You can't just open a menu to upgrade this thing. You need an altar. Specifically, the Altar of Darkness.
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Most people get lost looking for this one. It's tucked away in the Unte Ruins, located in the lower Scadu Altus region. You get there by going through the Shadow Keep, finding the hidden coffin near the Main Gate Plaza, and taking a scenic (and deadly) boat ride down to the Castle Watering Hole.
Once you’re at the Unte Ruins, you’ll see a bunch of dormant Furnace Golems. One of them is blocking the entrance to a small building. You have to wake it up. Throw a Hefty Fly Pot or a Hefty Furnace Pot into its head basket from the balcony above.
Once it stands up, try not to get stomped. Slip into the room it was guarding. Inside, you’ll find the altar. If you have the Stone-Sheathed Sword (or the Sword of Light), you can interact with the altar to transform it into the Sword of Darkness.
Why This Weapon Actually Slaps (and When It Doesn't)
Let’s talk stats. The Sword of Darkness is a Faith-scaling straight sword. Its unique Skill, "Darkness," is what makes it worth the headache.
When you trigger the skill, your character unleashes a cloud of literal shadow. It deals holy damage—ironic, I know—but the real value is the debuff. It reduces the enemy's holy damage negation.
- Scaling: It hits an B or A in Faith depending on your upgrade level.
- Weight: It’s light. You can power-stance this easily.
- The Look: It’s pitch black. It looks like a void in the shape of a blade.
If you’re running a pure Faith build or a Paladin-style setup, this is a top-tier sidearm. You use the Skill to soften up a boss like Messmer or Romina, then follow up with a heavy-hitting incantation or a different holy weapon.
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However, if you’re a Strength or Dex main? This is trash for you. Don't bother. The physical damage is lackluster compared to something like the Milady or even a standard longsword with a heavy infusion. It’s a niche tool for a niche build.
The Light vs. Darkness Debate
A lot of players ask: should I just stick with the Sword of Light?
The Sword of Light has a beam attack. It feels more "heroic." But the Sword of Darkness feels more strategic. In Elden Ring, defense reduction is usually better than a flat damage burst, especially in the late-game DLC boss fights where everything has 40,000 health and ignores your puny attacks anyway.
If you're playing co-op, the Sword of Darkness is arguably better because that holy negation debuff applies to everyone's attacks. Your buddies using Sacred Relic Swords will thank you.
The Secret Third Altar
There are actually three altars in total.
- Fog Rift Catacombs: Usually where you find the sword.
- Unte Ruins: The Darkness Altar.
- Ancient Ruins of Rauh: The Light Altar.
The Rauh altar is a nightmare to find. You have to navigate a series of invisible walkways or very narrow ledges near the West Rauh ruins. If you accidentally turn your sword into Light and want Darkness back, you have to run all the way back to the Unte Ruins.
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It’s a hassle. Honestly, pick a side and stay there until you’ve finished the DLC.
What Most People Get Wrong About the Scaling
There's a common misconception that the Sword of Darkness scales with Arcane because it's "dark." It doesn't.
FromSoftware has a weird habit of making "dark" things scale with Faith in this game (think of the Confessor class or the Godslayer incantations). If you’ve dumped all your points into Arcane thinking this would be your new Rivers of Blood, you’re going to be disappointed.
Check your stats before you commit the Somber Smithing Stones. You’ll need a solid 25-30 Faith just to make it viable, and ideally 60+ to see the damage actually move the needle on bosses like the Promised Consort.
Actionable Steps for Your Build
If you’re ready to pull the trigger on this weapon, here is exactly how to optimize your run:
- Grab the Sword: Head to Fog Rift Catacombs. Don't miss the elevator trap. Ride the top of the cage.
- Unlock the Watering Hole: Find the hidden ladder in Shadow Keep (near the burning boats and the painting room) to reach the coffin.
- Wake the Golem: Craft Hefty Furnace Pots. You need Visage Golems or Furnace Visage items for this.
- Transform: Go to the Unte Ruins altar.
- Upgrade: This uses Somber Smithing Stones. Since it's a DLC weapon, you likely already have the Bell Bearings to buy stones [1] through [9].
- Pairing: Use the Shard of Alexander. It boosts the damage of the Darkness skill significantly. Also, consider the Sacred Scorpion Charm, even though it lowers your physical defense. The trade-off for that extra holy damage is usually worth it if you’re good at rolling.
The Sword of Darkness is a statement piece. It says you’ve explored the deepest corners of the map and solved the puzzles most people skipped. It's not the most broken weapon in the game—looking at you, Bloodfiend’s Arm—but it’s one of the most unique. Just make sure you actually like the color black, because you’ll be staring at it for a long time.