Heart of the Fist Phantom Blade Zero: Fist Fragment Shell & Worldbreaker Fist

Heart of the Fist (拳心 — “A Tempered Resolve Still Endures”) is the final entry in the Iron Gauntlets’ temper chain and one of the last tales most players finish. It is short — one conversation, one gravestone, one incense offering — but it assembles the Worldbreaker Fist, the Soul Temper material that turns the Iron Gauntlets from a shield-breaker into a shockwave artillery piece. Think of it as set collection with a body count: you have been carrying one half of a dead master’s fist since the Village of Lu, and this tale is where the other half surfaces.

The Prerequisite: Fist Fragment Core From Young Mistress

The Worldbreaker Fist is assembled from two fragments, and the game expects you to already hold the first one. Fist Fragment: Core drops from the extended Mu Xiaokui Lakeside fight in the Village of Lu — the guardian phase that only triggers if you collected all five ribbons in the Young Mistress quest before the chapter finale. Game8 states this explicitly as the prerequisite chain: no ribbons, no guardian phase, no Core, and Heart of the Fist cannot pay off.

The Core’s item card tells you whose fist it was: a fragment from the Iron Fiend’s gauntlets, “still imbued with unwavering martial resolve,” raised only against formidable foes to protect those worth protecting. If that description reads like a eulogy, it is one — by the time you claim the Shell, you will know why.

Step 1: Iron Fiend at the Sha-Chi Tower 6th Floor

Heart of the Fist opens during the late-game return to Crimson Forest, when the region reopens as the snow-covered Frozen Mirrorwood after Mirage Estate. Per KeenGamer’s All 33 Tales table, the trigger floor is specific: climb the Sha-Chi Tower and ring the 6th Floor bell, then speak with Iron Fiend standing nearby — AllThingsHow measures him at roughly 20 meters from the bell, and Maxroll’s Frozen Mirrorwood walkthrough has you talk to him on the way up to the roof.

The conversation is the quest: Iron Fiend asks you to visit his master’s grave in Mirrorwood and offer incense on his behalf. The quest log updates with a single objective — “Find the Iron Fist Master’s gravestone in the snow-covered Mirrorwood” — and per AllThingsHow, the gravestone is inert until this talk happens, so do not detour to the Burial Grounds first.

Note who else is standing on this floor. The 6th Floor is also the staging ground for Use It Against Them, the sparring rematch against Jade Dancer and Iron Fiend that demands Fiend Saws and Iron Gauntlets and pays the Heel Reinforcement Part. Maxroll sequences both in one tower visit — finish the spar, claim the Supreme Order Token from Mu at the roof, then ride the bell back down. Our all-tales roster tracks the pair together for exactly this reason.

Step 2: The Gravestone at the Burial Grounds

Fast travel to the Burial Grounds bell and head southwest through the snow-covered Mirrorwood. AllThingsHow measures the walk at roughly 39 meters at the same elevation; Maxroll describes it as the tomb in the center of the burial area; KeenGamer and PowerPyx both mark it as the large stone gravestone of the Iron Fist Master. You cannot miss it — it is the only monument of its size in the clearing.

Interact with it. Soul burns the incense, a short cutscene plays, and the tale pays out Fist Fragment: Shell. Its card is the Core’s mirror: “A fist fragment left at the Iron Fist Sect Master’s final resting place. Its forbidding iron shell remains, but inside, it is completely hollow.” Shell and Core — the shape and the resolve — and with both in your inventory they combine into the Worldbreaker Fist. Maxroll has the assembly resolve at the gravestone itself; Game8 has it combine automatically the moment the Shell is awarded with the Core already banked. Either way, one grave visit closes the tale.

Step 3: Temper the Iron Gauntlets

Bring the Worldbreaker Fist plus 5,000 Remnant Dust to Myst’s tavern — or any bell, once tempering is unlocked — and Soul Temper the Iron Gauntlets. The tempered art is Fist Wave: every R2 gauntlet swing releases a forward shockwave. The synergy writes itself — the shockwaves build Fist Focus from outside melee range, and a full gauge still feeds the eight-second main-weapon damage buff that makes the gauntlets worth carrying. For the full material economics, see the Soul Tempering guide and the Soul Temper materials index, where the Worldbreaker Fist sits as the Iron Gauntlets’ designated material.

One more reason to finish the set: the gauntlets themselves come from Stone Hand Iron Fever back in the early Crimson Forest, so the entire chain — boss drop, ribbon-gated fragment, gravestone fragment — spans most of the game. It is the longest equipment arc in Phantom Blade Zero, and this two-minute tale is its final domino.

Is Heart of the Fist Missable?

No — and deliberately so. The tale only becomes available in the post-Mirage Estate window, after every cutoff that could lock it has passed, per KeenGamer’s roster and Game8’s unlock table. If you skipped the Young Mistress ribbons, the Core is what you lost, not the Shell; see the Young Mistress walkthrough for the five ribbon locations and the hard cutoff before the village finale.

Frequently Asked Questions

Do I need to beat the Use It Against Them sparring first?

No — the sparring and Heart of the Fist are independent tales that share the 6th Floor. Maxroll runs them back-to-back because it is convenient, not required.

What if I interact with the gravestone before talking to Iron Fiend?

Nothing. Per AllThingsHow, the gravestone only becomes interactive for this tale after Iron Fiend’s request, so climb the tower first.

Is the Worldbreaker Fist a weapon?

No — it is a Soul Tempering material consumed to upgrade the Iron Gauntlets, assembled from the two Fist Fragments. The gauntlets stay; the fist is spent on Fist Wave.

Sources: keengamer All 33 Tales walkthrough and Soul Temper materials coverage, maxroll Frozen Mirrorwood walkthrough, Game8 Heart of the Fist walkthrough, AllThingsHow Heart of the Fist and Iron Gauntlets guides, PowerPyx via community trackers, wikily material data (October 29 - November 5, 2026).