Mortal Shell 2 Great Martyr's Blade Guide: Location, Build & Best Tarstones

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Last Updated: August 20, 2026

The Great Martyr's Blade is one of the most powerful heavy weapons you can pick up in Mortal Shell 2. Its huge reach, heavy stagger, strong running attack, and weapon-specific Spiral Surge skill make it particularly effective against tougher enemies.

The catch is getting it. The weapon is hidden inside Martyr's Prison, and reaching the dungeon can be confusing if you accidentally head toward Martyr's Tomb or miss the mechanism that opens the prison route.

This guide covers the Great Martyr's Blade location, Martyr's Prison route, dungeon puzzle, Big Boi achievement, combat mechanics, Tarstones, Shell pairings, upgrades, and build recommendations.

Quick Answer

The Great Martyr's Blade is found in Martyr's Prison, beside the Citadel of Penance. Once inside, you'll need to work through the prison, activate its hidden controls and shoot the circular mechanism above the final gate to reach the weapon. Picking it up also unlocks Big Boi. 

A header image for the Mortal Shell 2 Great Martyr's Blade guide, showcasing the massive heavy greatsword on its pedestal inside Martyr's Prison near the Citadel of Penance. Text callouts highlight its location, the key Spiral Surge skill, and the target mechanism required to unlock it.

How to Get Great Martyr's Blade

Quick answer: The Great Martyr's Blade is found inside Martyr's Prison, beside the Citadel of Penance in the Gloomshade Grove area.

The basic route is:

  1. Reach Gloomshade Grove.
  2. Make your way toward the Citadel of Penance.
  3. Enter Martyr's Prison rather than Martyr's Tomb.
  4. Work through the prison's locked cells and combat rooms.
  5. Activate the hidden wall mechanism.
  6. Open the final gate by hitting the circular mechanism above it with a sidearm or crossbow.
  7. Defeat the remaining enemy.
  8. Take the Great Martyr's Blade from the pedestal.

Picking up the weapon also unlocks the Big Boi achievement. You don't need to equip or upgrade it for the achievement to trigger.

Great Martyr's Blade Location

The weapon is located in:

  • Region: Fainweald
  • Area: Gloomshade Grove
  • Landmark: Citadel of Penance
  • Dungeon: Martyr's Prison

Don't confuse Martyr's Prison with Martyr's Tomb

This is one of the easiest mistakes to make.

The Great Martyr's Blade is in Martyr's Prison, not Martyr's Tomb.

If you're following a map and end up heading toward Martyr's Tomb, turn back toward the Citadel of Penance side of Gloomshade Grove. Martyr's Prison is attached to the Citadel area.

How to Reach Martyr's Prison

There are a couple of ways the surrounding area can be approached, but the important thing is reaching the Citadel/Martyr's Prison section of Gloomshade Grove.

Citadel Gate route

If the main Citadel gate is still closed, you'll need to progress far enough to obtain the Citadel Gate Lever.

The Bloodcursed Lithopod is tied to this progression and provides access to the main route.

Alternate access

There's also an alternate route involving the candle teleport near the One-Legged Wolf Beacon, which can bypass the main gate and place you inside the prison section.

Because the game offers more than one way through this area, don't assume the main gate is your only option if you're trying to reach Martyr's Prison.

Martyr's Prison Walkthrough

Once you're inside, the dungeon itself is relatively compact, but there's a mechanism that's easy to miss.

  1. Reach the lower route – From the surrounding Gloomshade Grove area, follow the route toward the Holding Cells area. Look for the glowing staircase near the Holding Cells well.
  2. Activate the teleport object – Continue into the lower area and interact with the conspicuous container/object. This teleports you into a locked cell inside Martyr's Prison.
  3. Break out of the cell – Attack the cell-door lock to escape. Move into the corridor and deal with the enemy waiting outside.
  4. Find the wall control – Continue through the next section until you reach the control on the wall. Activate it. This raises the gate leading toward the main combat area. If you don't see the message that a gate has lifted, you've probably missed this control.
  5. Enter the main combat room – You'll eventually enter a larger circular combat area. Clear the enemies inside before looking for the route onward. The encounter can make it appear that you're trapped, but the room contains everything you need to continue.
  6. Replenish your ranged ammunition – Look for the glowing tree inside the area. Breaking it can provide ranged ammunition, which is important for the next mechanism.
  7. Shoot the circular ring – This is the part most likely to make you think the dungeon is blocked. If the portcullis won't open, look above the gate. You'll see a circular ring/mechanism. Equip your sidearm or crossbow and shoot the ring. The gate opens, allowing you to continue.
  8. Defeat the remaining enemy – Go through the newly opened passage and defeat the large enemy waiting on the other side.
  9. Claim the weapon – Continue into the rear chamber. The Great Martyr's Blade is waiting on a pedestal. Interact with it to add the weapon to your arsenal.

Extra Loot Along the Route

Don't rush through Martyr's Prison if you're still building your character.

The route also contains useful upgrade materials, including:

  • 2× Laterite
  • Common Moonshine

Laterite is particularly useful for weapon and sidearm upgrading, so the trip can be worthwhile even if you're not immediately planning to use the Great Martyr's Blade.

How to Unlock the Big Boi Achievement

The Great Martyr's Blade has its own achievement/trophy:

Big Boi — Unlock Great Martyr's Blade.

The important part is the word unlock.

You don't need to:

  • equip the weapon,
  • upgrade it,
  • kill an enemy with it,
  • or finish the dungeon again.

Simply pick up the Great Martyr's Blade and the achievement should trigger.

Great Martyr's Blade Combat & Spiral Surge

The Great Martyr's Blade is designed around heavy attacks, reach, stagger and deliberate positioning.

It isn't the weapon to choose if you want extremely fast combos.

Instead, its strengths are:

  • Huge attack range
  • Strong stagger
  • High damage per hit
  • Powerful heavy attacks
  • Excellent running attack
  • Strong single-target pressure

The weapon also has its own special ability, Spiral Surge, which gives the Blade another powerful option beyond its normal attacks.

How to play it

A simple rhythm is:

Create distance → Sprint → Heavy Attack → reposition → punish

Against tougher targets, you can then look for opportunities to use the weapon skill or another heavy attack.

The important thing is not to treat the Great Martyr's Blade like a fast weapon. One well-timed attack is usually better than forcing an entire combo.

Why the Running Heavy Attack Is So Strong

This is arguably the biggest reason to use the Great Martyr's Blade.

The running heavy attack combines:

  • Forward movement
  • Large reach
  • High damage
  • Strong stagger
  • Safe attack timing
  • Excellent punish potential

The attack can also be used to close distance while attacking, making it particularly useful against enemies that constantly try to reposition.

The basic technique

Try:

Sprint → Heavy Attack → Recover → Sprint → Heavy Attack

Rather than standing directly in front of an enemy and trading blows, you're constantly moving into the target and using the running attack to punish openings.

The attack is especially effective against ordinary enemies because its damage and stagger can make short encounters extremely quick.

Against elite enemies

The running heavy becomes even more useful when you combine it with spacing. Wait for the enemy to commit to an attack, move outside its range, then use the running heavy to close the gap and punish.

Don't spam it blindly. The attack still consumes stamina and the Great Martyr's Blade's slower overall moveset means getting caught at the wrong time can be costly.

Best Tarstones for Great Martyr's Blade

Your Tarstone setup should complement the Blade's main strengths rather than trying to turn it into a completely different weapon.

The weapon supports multiple melee and support Tarstones, including Parasitic Stone, Arbiter's Prize, Acolyte's Stone, Unwieldly Stone, Magdalena's Memento, Shrike Stone, Deadman's Stone and Shattering Stone.

Best general setup

Shattering Stone is an especially natural choice for a heavy stagger-focused build. The Tarstone improves melee stagger damage, which directly supports the Blade's heavy-attack playstyle.

Parasitic Stone – Parasitic Stone gives you sustain by providing Leech when you defeat enemies. It's a useful choice for exploration and clearing groups because it reduces the pressure on your healing resources.

Deadman's Stone – If you're focusing more heavily on critical hits, Deadman's Stone improves melee Critical Chance. This is better suited to an offensive damage-focused setup than a pure stagger build.

Arbiter's Prize – Arbiter's Prize provides a Bloodcurse weapon infusion through Resolve. Use it when you want to build around elemental/infusion effects rather than simply maximizing stagger.

Unwieldly Stone – Unwieldly Stone lets you spend Resolve to perform a Charged Heavy Attack, making it a natural match for players who want to lean even harder into heavy attacks.

Recommended priority

For a straightforward first build:

Shattering Stone → Parasitic Stone → offensive/infusion choice

This gives you a useful combination of stagger, sustain and damage.

Best Shells for Great Martyr's Blade

One of the advantages of Mortal Shell 2 is that weapons aren't locked to a particular Shell, so you can build the Great Martyr's Blade around the playstyle you prefer.

⭐ Tiel — Best Aggressive Pairing

Tiel is a natural choice if you want to play aggressively. The idea is simple: Use mobility to avoid attacks, exploit openings, sprint into enemies, use the Blade's heavy attacks, and retreat before the enemy can retaliate. This combination rewards confident players who understand enemy attack patterns.

🛡️ Harros — Best Beginner Pairing

If you're still learning Mortal Shell 2, Harros is the safer recommendation. The Great Martyr's Blade already provides enormous damage and reach, so you don't necessarily need to maximize its offensive potential immediately. A more forgiving Shell lets you learn the weapon without turning every mistake into a death.

💪 Eredrim — Heavy Stagger Build

If your priority is making enemies stagger as frequently as possible, Eredrim is a strong pairing. Combine: Eredrim + Great Martyr's Blade + Shattering Stone for a deliberately heavy melee setup.

⚡ Proxima — Hybrid Build

Proxima is worth considering if you want to combine the Blade with additional ranged or elemental pressure. This produces a more flexible build than simply stacking heavy melee damage.

Best Seal for Great Martyr's Blade

Your Seal choice should depend on how you approach combat.

Vatra's Seal – Best for players who like to use Harden to absorb an attack before continuing their heavy assault.

Infinite Seal – A good option if you're comfortable with Perfect Guard and want to play around precise defensive timing.

Untarnished Seal – A more balanced choice if you don't want your build to revolve around one specific defensive mechanic.

Slayer Seal – The Slayer Seal can make combat considerably easier by improving sidearm and Riposte interactions, but remember that equipping it disables achievements on that save file. For a normal achievement-focused playthrough, that's an important consideration.

Great Martyr's Blade Upgrade Priority

Don't throw every resource into the weapon immediately if you still have important character upgrades to unlock.

A sensible progression is:

Early game: Obtain the Great Martyr's Blade → Make sure your Shell has the upgrades you need → Unlock the relevant Tarforge functions → Start upgrading the Blade → Add Tarstones that match your preferred playstyle.

Heavy stagger build: Prioritize: Great Martyr's Blade → Shattering Stone → Shell upgrades → supporting Tarstones.

Sustain build: Prioritize: Great Martyr's Blade → Parasitic Stone → Shell upgrades → offensive Tarstones.

The important thing is to avoid spreading rare upgrade resources across weapons you aren't actually using.

For the weapon-upgrade process itself, see our Mortal Shell 2 Tarforge Guide.

Great Martyr's Blade vs Axatana

These weapons appeal to very different players.

Great Martyr's Blade Axatana
Heavy greatswordTransforming weapon
Slow attacksFaster combat
Excellent reachMore versatile moveset
Strong staggerBetter combo flexibility
Running-heavy focusedMultiple combat forms
Best for deliberate playBest for adaptable play

Choose Great Martyr's Blade if you want: Huge weapons, High stagger, Long reach, Heavy attacks, Strong running attacks, Deliberate combat.

Choose Axatana if you want: Faster attacks, More flexibility, Different weapon forms, More aggressive combos.

Neither weapon completely replaces the other.

Is Great Martyr's Blade Worth Getting?

Absolutely—especially if you enjoy heavy weapons.

The Great Martyr's Blade has several things going for it:

  • You can obtain it relatively early.
  • It has excellent reach.
  • Heavy attacks deliver strong stagger.
  • The running heavy is extremely useful.
  • It supports multiple Tarstone-based builds.
  • It works with any Shell.
  • Picking it up also unlocks Big Boi.

Its main drawback is speed.

If you prefer rapid attacks and constant combos, the Axatana or another faster weapon may feel better.

But if your preferred strategy is: Wait for an opening → close the distance → land one enormous hit → stagger the enemy → reposition, the Great Martyr's Blade is an excellent choice.

Great Martyr's Blade Build: Quick Setup

For players who just want a build to copy:

  • Weapon: Great Martyr's Blade
  • Shell: Tiel for aggression / Harros for beginners
  • Main Tarstone: Shattering Stone
  • Sustain option: Parasitic Stone
  • Playstyle: Sprint Heavy + stagger
  • Defensive approach: Dodge or Harden rather than trading hits
  • Upgrade priority: Great Martyr's Blade + Shell first

If you prefer a more defensive build, switch to Harros and use Vatra's Seal.

Mortal Shell 2 Great Martyr's Blade FAQ

Where is Great Martyr's Blade in Mortal Shell 2?
It is inside Martyr's Prison, located beside the Citadel of Penance in the Gloomshade Grove area.

Is Great Martyr's Blade in Martyr's Tomb?
No. The weapon is in Martyr's Prison. Martyr's Tomb is a different location and can easily cause confusion when navigating this area.

How do I open the gate inside Martyr's Prison?
Activate the wall control in the prison corridor first. Later, if the final portcullis is closed, shoot the circular ring above the gate with your sidearm or crossbow.

What achievement does Great Martyr's Blade unlock?
Picking up the weapon unlocks Big Boi.

What is the best Tarstone for Great Martyr's Blade?
Shattering Stone is an excellent general choice because it increases melee stagger damage, which directly complements the Blade's heavy attacks.

Which Shell is best with Great Martyr's Blade?
Tiel is a strong aggressive pairing, while Harros is the better recommendation for beginners. Eredrim is attractive for a heavier stagger-focused setup.

Is Great Martyr's Blade better than Axatana?
Not universally. The Great Martyr's Blade is better for reach, heavy attacks and stagger, while Axatana is better suited to players who want speed and versatility.

Should I upgrade Great Martyr's Blade early?
Yes, if you enjoy heavy weapons and intend to keep using it. Don't spread rare materials across several weapons unless you're actively testing different builds.

Final Verdict

The Great Martyr's Blade is much more than another weapon-location collectible. Its combination of long reach, heavy stagger, powerful running attacks and flexible Tarstone setups makes it one of the most attractive heavy-weapon choices in Mortal Shell 2.

If you're having trouble reaching it, remember the two biggest route checks:

  • You're looking for Martyr's Prison—not Martyr's Tomb.
  • And inside the dungeon: If the final gate won't open, shoot the circular ring above it with your sidearm or crossbow.

Once you've picked up the Blade, you also get the Big Boi achievement, making the trip useful even if you ultimately decide another weapon better fits your build.

Guide for Mortal Shell 2

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