This guide provides a complete walkthrough for Castigator's Keep in Mortal Shell 2, detailing the path southeast from the Lonesome Spire, through the Vestige of Infinity, and into the expansive keep itself. The area contains multiple dungeons, several bosses, and numerous lesser foes, but also yields the Triarch Repeater sidearm.

Reaching the Ventrium Deposit

Begin by fast traveling to the Lonesome Spire Beacon and proceeding east. Instead of taking the main path, descend a slope to the left. Cross two bridges, dealing with Tarblighted Miners, then drop to a lower ledge. After clearing more Miners, cross the final bridge to a grassy area. Eliminate the Wretches and collect three Weltcaps. Head right to find nine Ventrium, but do not use the air current present.

Entering the Vestige of Infinity

Now, follow the main eastern path, defeating two Subjugated Sentries, a Knave on the bridge, and another beyond. In the next room, defeat a Brigand and collect Ventrium. Ascend the ramp, engage the Sentry, and then drop to a lower ledge to retrieve Laterite. Ride the air current back up and pass through the Bone Gate. Collect a Coin of Mammon from a statue on the left, then proceed through the archway to defeat a Sheep and obtain a Sheephead Totem. Take the right-hand bridge across the platform to collect two Laterite, then cross the left bridge to enter the Vestige Of Infinity.

Defeating the Starved Harridan

Upon entering the Vestige of Infinity, turn left to find a Galvanic Shard. Proceed through the gap in the wall opposite to face a boss arena. Drop down to initiate a fight with the Starved Harridan. This enemy is deceptively fast despite its lumbering appearance, and its projectile attacks can be chained with melee combos. Parry these attacks carefully, though its low damage makes the fight forgiving. Upon defeating the Starved Harridan, you will receive Voltaic Essence and a Voltaic Amber Tarstone.

Activating the Vestige Of Infinity Beacon

After the boss fight, approach the low section of wall up the ramp to the left of the entrance. Strike this wall to reveal the Vestige Of Infinity Beacon. Activate it to rest.

Reaching the Castigator's Keep Courtyard

From the Beacon, proceed clockwise around the arena to find an elevator. Use the lever to descend into Castigator's Keep. At the bottom, defeat a Gloom Seeker and enter the next room. Turn right, exit onto a balcony, and defeat an exploding Infested Wretch. Collect the Laterite behind it. Return to the room and take the exit in the far left corner, descending steps into the Castigator's Keep courtyard.

Clearing the Hall of Murmurs

Descend into the dungeon entrance ahead, after defeating a Grisha Hunter. Inside the Hall of Murmurs, clear Wretches and Shield Brigands. Strike an illusory white symbol on the right-hand wall to reveal a hidden area with a Leechtongue. Collect 700 Coin from nearby pouches. Proceed through the wooden door, defeat a Foul Knight guarding a chest with Laterite and a Gloombound Stone, and loot Ventrium by a fireplace. After defeating the Foul Knight, return the way you came, preparing to fight three more Foul Knights on your exit.

Obtaining the Map of Mammon [3]

Exiting the Hall of Murmurs, turn left and drop into the pond to defeat Grisha Hunters. Ascend small stone steps next to the wall to find two Common Moonshine. Drop off the near edge to find three more Grisha Hunters guarding a map statue. Defeat them and collect the Map of Mammon [3].

Conquering the Alchemist's Workshop

From the map statue, take the right path down and across a bridge, defeating two Roaming Heads and collecting Dorsalite. Use a Bone Gate to cross a gap. Cross the next bridge, defeat three Tarblighted Miners, and collect a Dorsalite. Enter the dungeon entrance nearby, which was opened by a projectile shot from a catapult, leading to the Alchemist's Workshop. Clear the first room of Miners and Tarred Corpses. Continue down steps, defeating a Batushka. Dodge an enchanted book projectile and find a Dorsalite by a Bone Statue. In a side room, collect Common Moonshine. Progress through a garden area, defeat another Batushka, and collect items. Pull a book from a bookshelf to reveal an illusory wall; dispel it and defeat a Cannibal Knight and a Tarred Archer. Lure and kill a Sheep in a cell to obtain a Sheephead Totem. Drink the Alchemical Elixir on the desk; after the disorientation effect wears off, defeat Mycellian Skulks in the revealed path and collect items. Use a lever to return to the main room. Take an elevator down, defeat Skulks, and fight a Slithering Corpseseeker. Destroy Gloom Tentacles and open chests for Clockwork Shardstone and an empty chest. Interact with an orb to exit.

Retrieving the Triarch Repeater from Blackwell Cavern

Back in the overworld, head right around a rock to defeat a Miner and collect Laterite. Follow a path of bridges between ring-shaped platforms, collecting Laterite and Dorsalite. Continue along the cliff edge, defeating three Grisha Hunters. Enter a dungeon entrance guarded by another Grisha Hunter. Before entering, proceed to a campsite at the end of the path to defeat three more Grisha Hunters and collect Common Moonshine. Enter the dungeon, Blackwell Cavern, and defeat four Wraiths in the dark. Collect Laterite and the Triarch Repeater. Deal with Mycellian Skulks and return to the overworld.

Entering the Keep from the East Side

Retrace your steps to the slope you passed earlier. Ascend the slope, dealing with Netopyrs in the trees. Collect two Coin Pouches, three Weltcaps, and an Egon's Stone. Return up the slope, collect three more Weltcaps, and call an elevator to ascend back into Castigator's Keep.

Activating the Castigator's Keep Beacon

As you exit the elevator, defeat two Subjugated Sentries on a wooden platform and collect a Justiciar's Stone. Collect a Synaptic Vessel on the stone floor. Descend steps, defeat a Foul Knight, and loot Laterite. Proceed through an archway, defeat a Knight of Mammon, and reach a Bone Gate. Turn around and defeat Foul Knights. Take the right path to the Castigator's Keep Beacon; activate and rest at it. Collect Common Moonshine. Proceed across a bridge to an area with three Cultists and a Neophyte Sester. Destroy the invulnerability torch to defeat them. Collect a Burnt Effigy and Dorsalite. Return across the bridge and head past it, turning a corner to find two Foul Knights. Defeat them and proceed back into the courtyard. Enter a room with two Infested Wretches and collect a Burnt Effigy. Exit, descend steps, and find two Weltcaps, a sitting spot, and a Devout's Chalice. Return to the Castigator's Keep Beacon.

Conquering the Viletongue's Domain

Enter the Beacon, loot a chest for 1000 Coin, and descend the elevator into Viletongue's Domain. Defeat a Wraith and two Foul Knights to collect Ventrium. Ride an air current, defeat another Wraith, and examine an inscription. Drink the Strange Concoction in the corner; this reverses movement and summons the Viletongue Batushka boss. Defeat the boss to normalize movement. Collect a Glimpse, a Viletongue Hedron Tarstone, and the Sage's Gate Lever. Use the lever, collect a Coin Pouch, and cleanse corruption for another Glimpse and an Ovum.

Meeting Egon and Offering Gloom

Facing the Beacon, head right and pull a lever to open a shortcut gate. Ascend a wooden ramp into a tower to find Egon. Speak with him and interact with the offering cup at the top. Offer Gloom, ideally in two installments: 9,999 Gloom first, then 10,000 Gloom. This maximizes the bonus Gloom received upon Egon's death. Collect double the invested Gloom from his corpse. Rest at the Beacon to prepare for the next area.