Quick answer: In Pangzhen, find Myst in the Order’s underground tavern, choose “Soul Temper,” and press P on the upgrade screen. Each upgrade requires 5,000 Remnant Dust and one designated key item.
Phantom Blade Zero’s regular weapon upgrades and Soul Tempering use different progression tracks. Myst transfers memories from objects connected to a weapon into the weapon itself. She considers a weapon without this process to have a body, but no spirit. A Soul Temper either transforms a weapon into a different named weapon or grants a named effect to the weapon you currently have.
Where to find Myst
Myst sits at a table inside the Order’s underground tavern in Pangzhen, which you reach during the story quest Town of Death. Look for a woman with long silver-blue hair behind a low table set with a teapot and cups. Shelves of jars line the wall behind her. If you have not reached the tavern yet, the Pangzhen route covers the way into town.
Her talk menu lists “About the Illusory Pipa,” “About the Boatmaster and Meigu Lake” and “Soul Temper”. Move through the options with W and S, confirm with Space, and back out with Esc. Once you’ve heard both conversations, the menu trims down to “Soul Temper” and “Leave”.
How to Soul Temper a weapon
Bring 5,000 Remnant Dust and the key item for the weapon you want to upgrade. Each upgrade has its own key item, and Remnant Dust also pays for normal weapon upgrades at the same screen.
Soul Temper upgrades for main weapons
Three main weapons transform into new named weapons, and the rest gain a named effect.
| Weapon | Type | Soul Temper upgrade | Key item |
|---|---|---|---|
 Sanguine Twin | Dual-Wield | Shadowless Edge | Chaos Twin Daggers |
 Tianxuan Bronze Sword | One-Handed | Effortless Action | Bronze Essence |
 Sanguine | One-Handed | Infernal Rouge | Bastion of Mó Mask |
 Scarlet Wraithblade | Two-Handed | Lingering Grudge | Embroidered Shoes |
 Sanguine Reach | Two-Handed | Blazing Edge | Flaming Grip |
 Jagged Steel | One-Handed | Open Wounds | Iron Butcher Mask |
 Outlaw Warblade | Two-Handed | Ruthless Outlaw | Six Paths Warrant |
 White Serpent & Crimson Viper | Dual-Wield | Hundred-Knot Serpents | Serpent’s Memory |
 Fiend Saws | Dual-Wield | Endless Fiend Form | Heel Reinforcement Part |
The upgrade screen describes each effect this way:
- Shadowless Edge: “Transformed through Soul Tempering into Shadowless Edge.”
- Effortless Action: “Even while Guard-Broken, hold the block button to block at the cost of a small amount of HP.”
- Infernal Rouge: “Soul Tempers into Infernal Rouge, the heirloom weapon of the Bastion of Mó.”
- Lingering Grudge: “Attacking enemies within Red Spider Lilies builds their Red Flower Gauge. Filling the gauge triggers an explosion. While you or allies are within Red Spider Lilies, all Sha-Chi Consumption is reduced and healing received is increased.”
- Blazing Edge: “Transformed through Soul Tempering into Blazing Edge.”
- Open Wounds: “Attacks still build the enemy’s Bleed Gauge even when blocked. Has no effect on Puppets, Golden Bodies, or Phantom Bodies.”
- Ruthless Outlaw: “The longer Recoverable HP is retained, the greater the increase in damage dealt, up to 25%.”
- Hundred-Knot Serpents: “When recalling Crimson Viper with its key combination, summon Hundred-Knot Serpents to attack. The longer the Crimson Viper short blade remains away from Soul, the more Hundred-Knot Serpents are summoned.”
- Endless Fiend Form: “After Fiend-Aura Erosion erupts on an enemy, all attacks against them become unblockable for 3 seconds.”
Soul Temper upgrades for Phantom Edges
Phantom Edges sit under their own tab and follow the same cost rule.
| Phantom Edge | Type | Soul Temper upgrade | Key item |
|---|---|---|---|
 Bastion | Artifice | Fierce Reprisal | Border Banner |
 Fire Meteor | Martial | Bone-Eating Ghostfire | Everlasting Flame |
 Kuye Temple Prayer Beads | Summoning | Golden Formation | Kuye Temple Sutra |
 Iron Gauntlets | Martial | Fist Wave | Worldbreaker Fist |
 Hunter’s Chain Sickle | Martial | Gleaming Hook | Alloyed Scythe Blade |
 Dread Axe | Destructive | Rapid Charge | Blood Oath Dagger |
- Fierce Reprisal: “Reprisal Shockwave unleashes one additional shockwave.”
- Bone-Eating Ghostfire: “Enhances all moves. Against enemies burning with Phosphor Flame, greatly increases damage dealt and Sha-Chi Depletion.”
- Golden Formation: “Upgrades the 3 summoned Bronze Men into a Fist Gold Man, a Staff Gold Man, and a Blade Gold Man. They retain all weapon upgrades previously applied to the Bronze Men.”
- Fist Wave: “Each attack releases a Fist Wave forward.”
- Gleaming Hook: “The chain’s power is increased, allowing it to deal the same damage as the sickle blade. When the sickle blade hits an enemy, it depletes more Sha-Chi and builds the enemy’s Bleed Gauge. When the gauge is full, it triggers Blood Loss. Has no effect on Puppets, Golden Bodies, or Phantom Bodies.”
- Rapid Charge: “Increases charge speed by 30%.”
Key items for other weapons
The tables above cover the weapons and Phantom Edges Soul carried when the menu was opened during Town of Death; other weapons have their own key items. The Thunder Core’s item card, for example, says it is used to Soul Temper the Thunder Spear, and the Thunder Core sits in a chest in Pangzhen. The Phantom Blade Zero weapons list covers the rest of the gear.
Myst’s other talk options
About the Illusory Pipa: Myst says the pipa belonged to the Chord, Lady Inanis’s daughter, and that Inanis made it for her. Its strings, head and backplate are missing, and if you bring all three back she can restore it. The Broken Illusory Pipa guide covers the instrument itself.
The same talk turns to Lake Meigu. Myst describes it as always shrouded in mist, with a layer of Sha-Chi over the water that brings on hallucinations, so boatmen and passengers have thrown themselves in over the centuries. Crossing it takes a Sha-Chi-powered boat.
About the Boatmaster and Meigu Lake: the Boatmaster vanished when the sickness swept through Pangzhen, but one of the Order’s boats may still be moored at his dock. Myst cannot say whether it still works.
