You've probably spent hours wandering the Shaded Castle, wondering why FromSoftware decided to fill a swamp with slow-moving statues and toxic sludge. It’s a miserable place. But tucked away in a chest, guarded by a Cleanrot Knight who really doesn't want you there, lies the Valkyrie's Prosthesis.
It’s just a key item.
Usually, key items in Elden Ring are boring things like glintstone keys or medallions that sit in your inventory and look pretty. This one is different. It’s the catalyst for one of the most heartbreaking, mechanically rewarding, and lore-heavy questlines in the entire game. If you miss this gold-plated arm, you're effectively locking yourself out of some of the best talismans for high-dexterity builds.
Honestly, the game doesn't give you a roadmap. You just find this prosthetic limb and, if you’ve been paying attention to the NPC dialogue, you might remember a certain one-armed girl shivering in a church in Caelid.
Where the Valkyrie's Prosthesis is Hiding
Most players stumble into the Shaded Castle while exploring the Altus Plateau. It’s that greenish, murky canyon north of the Lux Ruins. To get the Valkyrie's Prosthesis, you need to head to the northernmost part of the castle. Don't get distracted by the boss in the center tower just yet.
Look for a room on the elevated western ramparts.
Inside a small, unassuming room, a single Cleanrot Knight stands guard. These guys are annoying. They poke, they inflict Scarlet Rot, and they have way more poise than they should. Kill him or sprint past him—I usually just sprint—and open the chest. There it is. A mechanical arm made of unalloyed gold, designed specifically for someone who intends to wield a blade again despite their afflictions.
It’s heavy. It’s ornate. And it belongs to Millicent.
Why Millicent Needs This Thing
Millicent is basically the "mini-Malenia" of Elden Ring. When you first meet her at the Church of the Plague, she’s dying of Scarlet Rot. You save her with a gold needle, but she’s still missing her right arm. She can't fight. She can't fulfill her destiny or find Malenia without a way to hold a sword.
Giving her the Valkyrie's Prosthesis changes her entire AI behavior.
Once she has the arm, she moves from the Altus Plateau to the Windmill Village (Dominula). If you've already cleared that creepy village where the grandmas dance around skinless corpses, you'll find her standing near the bonfire after the Godskin Apostle boss fight. She's actually grateful. It's one of the few moments of genuine warmth in a game that usually tries to eat you.
The Mechanics of the Quest
The quest is long.
- Give the arm to Millicent at Erdtree-Gazing Hill.
- Meet her at Dominula, Windmill Village.
- Find her again at the Ancient Snow Valley Ruins in the Mountaintops of the Giants.
- Talk to her at the Prayer Room in Elphael, Brace of the Haligtree.
It’s that last part where things get messy. You eventually have to choose. Do you help her fight off her four sisters, or do you betray her?
If you help her, you get the Rotten Winged Sword Insignia. This is arguably the best talisman for anyone using fast weapons like Twinblades, Curved Swords, or Katanas. It boosts your attack power massively with every successive hit. If you betray her? You get Millicent's Prosthesis—a different talisman that gives you +5 Dexterity and a smaller version of that consecutive hit bonus.
People argue about which is better. Personally, the Rotten Winged Sword Insignia is the objective winner for pure damage, but getting both requires a second playthrough or a very generous friend in co-op.
The Lore Behind the Gold
Why is it called the Valkyrie's Prosthesis?
The item description mentions it was a "custom-made" piece for a one-armed valkyrie. In the context of Elden Ring, "Valkyrie" almost always refers to the daughters of Malenia or Malenia herself. The Shaded Castle is owned by the Marais family. Maleigh Marais, the guy you fight on the shaded castle greens, was obsessed with Malenia. He was a simp, basically.
He worshipped her as a goddess of rot and gathered "prosthetics" and "memorabilia" related to her.
This suggests the arm wasn't just a random piece of junk. It was a holy relic to the Marais family, a replica or a discarded prototype of the arm Malenia herself wears. When you give it to Millicent, you aren't just giving her a tool; you're giving her a piece of her mother's (or sister's, the lore is blurry) legacy.
Breaking Down the Stats
It’s worth noting that the item itself doesn't have "stats" because you can't wear it.
You aren't the one who gets the +5 Dex yet. That only comes later when you finish the quest and receive the talisman version. A lot of new players get confused here. They find the Valkyrie's Prosthesis in the castle and try to equip it, thinking they’ve found a cool new gear piece. Sorry to burst the bubble—it's a delivery mission.
You’re the courier for a prosthetic limb.
What Most People Get Wrong About the Shaded Castle
Don't go in there underleveled.
The poison is one thing, but the "Revenants" in the lower courtyards are the real run-enders. If you're hunting the prosthesis, stick to the rooftops. The pathing in the Shaded Castle is vertical. If you stay in the muck, you're going to get bogged down by slow movement and those multi-armed screeching horrors that teleport behind you.
Also, make sure you've talked to Millicent at the Erdtree-Gazing Hill before you go into the castle.
If she isn't there, the game sometimes glitches the trigger for the prosthesis dialogue. You want her sitting there, looking sad about her missing arm, before you show up with the gold-plated solution.
Final Steps for Your Build
If you are running a Dexterity build, do not ignore this.
The difference in DPS (damage per second) between having the Rotten Winged Sword Insignia and not having it is staggering. We're talking about a 6%, 8%, and 13% damage increase as you land hits. If you're using something like the Hand of Malenia or Rivers of Blood, that's the difference between a boss phase-shifting or just dying outright.
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Next Steps for Your Playthrough:
- Travel to the Altus Plateau: Head to the "Erdtree-Gazing Hill" Site of Grace and ensure Millicent is there. If she’s not, you need to go back to Gowry’s Shack in Caelid and finish the needle quest.
- Infiltrate the Shaded Castle: Go to the northern ramparts. Ignore the central hall and head straight for the room guarded by the Cleanrot Knight.
- Don't Kill the Boss Yet: You can get the prosthesis without fighting Elemer of the Briar. Save him for later when you actually want his Greatshield or Sword.
- Return to Millicent: Hand over the arm immediately. This unlocks her as a summon for several difficult late-game bosses, which makes your life a lot easier.
The Valkyrie's Prosthesis is more than a hunk of metal. It’s the key to the most powerful talismans in the Lands Between and the only way to see Millicent's story through to its (admittedly depressing) end. Go get it.