Mortal Shell 2: How to Get the Ballistazooka in Sentry’s Grave

The Ballistazooka is the hardest-hitting sidearm in Mortal Shell 2, and it is also one of the slowest. It fires a heavy ballista bolt with a long draw time and only two shots in reserve, so it functions as a punish tool rather than a weapon you spam. Getting it means crossing the southern half of Mammon and clearing a dungeon boss, not looting a chest.

Quick answer: Travel to the Gate of Mammon beacon, enter the Sentry’s Grave dungeon at the base of the Lonesome Spire, descend to the lowest level, and kill the Subjugated Guardian mini-boss. The Ballistazooka drops automatically when it dies.

Ballistazooka weapon profile

The weapon’s in-game text sets expectations plainly.

Heavy and unwieldy, scholars argue if the weapon was ever used in battle or just for executions in Marrow.

Property	Detail
Slot	Sidearm
Attack style	Slow, high-damage ranged projectile
Ammo	Two shots
Dungeon	Sentry’s Grave (Lonesome Spire, Ruins of Mammon)
Drop source	Subjugated Guardian mini-boss
Upgrades	Tarstones, applied at the Tarforge

Because the draw is long, the Ballistazooka is best used against a staggered or Broken enemy, or to soften something before you close the gap. It complements a melee build rather than replacing one.

What you need before heading to Mammon

Access to the region comes from cleansing the corruption on top of Marrow Keep, which opens the jump pad to the Outskirts of Mammon. Enemies in the southern half of the map hit considerably harder than anything in the north, so bring levels and healing before you commit.

If you want the location marked on your map first, Merrick in Marrow Keep sells the Location: Ballistazooka map fragment for 500 coins. It is optional. The map only places a marker in the general area and does not open the dungeon or shorten the route.

Route from the Outskirts of Mammon to the Gate of Mammon

Start at the Outskirts of Mammon beacon and head west through the Deserted Slums, past the soldier camps and rope bridges. A bone gate at the far end marks the approach to the next beacon.

Player character crossing a wooden bridge toward open ground on the route west through Mammon — The bridge crossings on the way west out of the Deserted Slums. Image: Cold Symmetry

Light the Abandoned Outpost beacon, then push on toward the High Lord’s Terrace beacon. This is a safe restart point if the fights ahead go badly.

From High Lord’s Terrace, cut through the High Lord’s Keep interior and up the stairs to reach the High Lord’s Courtyard beacon. Skeletal enemies patrol the stairwells here and can be run past if you would rather save resources.

Player climbing stone stairs inside High Lord's Keep while a skeletal enemy blocks the way — The stair climb through High Lord’s Keep toward the Courtyard beacon. Image: Cold Symmetry

Follow the trail up from the Courtyard, past the miner enemy blocking the archway, and keep climbing until you reach the Gate of Mammon beacon. If you lose your bearings, look up and steer toward the enormous structure looming over the area.

Finding the Sentry’s Grave dungeon entrance

The entrance sits at the base of the Lonesome Spire, the tall tower with a merchant trading at its peak, southwest of the Outskirts of Mammon beacon. You can approach it by descending from the top of the spire or by climbing up from the village full of casket enemies.

From the Gate of Mammon beacon, head northeast toward the castle and climb the wooden staircase. At the top, turn left to face a doorway guarded by several soldiers.

Go through that door into the circular hallway and keep following it without stepping back outside. Pass the halberd-wielding knight and continue into the room beyond.

In that room, look to the right, just before the door leading to the next flight of stairs. That is the dungeon entrance. Take the stairs down and ride the elevator to reach Sentry’s Grave proper.

Getting through Sentry’s Grave to the boss arena

The dungeon is packed with ballista-head enemies that fire lightning-infused bolts. They barely move, and each one makes an audible string-pull noise before it shoots, so a dodge on that cue avoids most shots. Running past them is the efficient play, since you want your healing intact for the fight at the bottom.

Player moving through a rubble-strewn stone passage inside Sentry's Grave — Rubble-choked corridors inside Sentry’s Grave. Image: Cold Symmetry

Keep descending. Some routes are hidden behind wooden barriers that need breaking, and the objective is always downward rather than sideways. The boss sits on the lowest level, so any path that gains height is the wrong one.

Player crossing a candlelit stone chamber on the way down through the dungeon — One of the candlelit chambers on the descent toward the arena. Image: Cold Symmetry

When you reach the long hallway, the Subjugated Guardian’s health bar appears while you are still approaching. Archers on the ledges above will open fire, and most of them cannot be reached. Ignore them and run for the arena.

How to beat the Subjugated Guardian

The Guardian is an upsized version of the ballista enemies, and its shots burst into clusters that leave fire on the ground. Equipping the Burnt Effigy before the fight reduces the burn damage if you keep catching alight.

Clear or bait away the weaker ballista enemies on the ledges around the arena so you are not taking chip damage from three directions during the fight.

Stay close to the Guardian. It has poor mobility, and crowding it prevents it from lining up repeated cluster shots. Pinning it toward the back of the arena also puts distance between you and the ranged enemies.

Watch for the tells. A low groan and a slight backward tilt of its head both signal an incoming shot, so clear the entire area it is aiming at rather than dodging through it. Outside of those windups it is open, so attack freely and dodge the headbutt.

Confirming you have the Ballistazooka

The weapon is awarded the moment the boss dies, alongside a Gloom and coin payout. No chest to open and no follow-up pickup exists, so if the drop notification appeared, it is yours.

Reward screen showing Gloom and coin gains after defeating the dungeon mini-boss — The Gloom and coin payout that lands alongside the sidearm drop. Image: Cold Symmetry

Open the inventory and check the sidearm list to verify it. Trying to equip it while another sidearm is in the slot returns a “Sidearm Already Equipped” prompt, which means you need to swap the existing one out first. You can teleport straight back to the dungeon entrance afterwards.

Tarstones that work with the Ballistazooka

Tarstones are slotted at the Tarforge and are how the sidearm scales past its base damage. A ranged critical setup suits it well, since the low ammo count means each shot has to matter.

Tarstone	Effect and source
Fusillade Stone	Fires all remaining ammo at once with raised crit chance and damage. Cleanse the Winterglass Lake Beacon in the Conquered Temple region.
Corroded Stone	Adds three extra damage instances per hit, then ticks a share of the original damage every 7 seconds for 30 seconds. Cleanse the Sunken Village Beacon in the Glutted Mire.
Deadeye Stone	Increases critical damage.
Marksman’s Stone	Increases critical hit chance.
Emberseed Stone	Adds a Burn infusion to shots.

Fully invested, that combination reaches roughly 53 percent crit chance and +140 percent crit damage on top of Burn. The full compatibility list is much wider and includes Charged Stone, Enfeebling Stone, Fulminant Stone, Infested Stone, Ironpiercer’s Stone, Pulse Stone, Rupturing Stone, Shuddering Stone, Siegebreaker’s Stone, Spite Stone, Weeping Stone, Volatile Fragment, Confessor’s Keepsake and Tarblighted Trophy.

Note: none of this changes the draw speed. However you build it, the Ballistazooka rewards patience over volume, which is why it pairs best with a melee kit that can create the opening in the first place.