SULFUR Castle Guide: Clear the Castle and Beat Saint Lucia

Clear the Hedge Maze, beat the four-level Dungeon, then fight through the Castle's four levels to Saint Lucia in the throne room — that is the full route from the maze exit to the area boss. This SULFUR castle guide covers the entry route, the enemies, the mini-boss, and the Lucia fight in order. SULFUR 1.0 launched on October 28, 2026, so this reflects the full release (official Steam page).

Before you enter: preparation

The Castle sits behind the Hedge Maze, which you reach after clearing the Sewers. The Hedge Maze itself is a short but disorienting area: follow the castle visible in the background and you will reach the exit without needing a map. The sulfur-covered enemies with eyes along the way only take damage when you hit the eyes, and they regenerate — down them with eye hits, then finish them with a grenade or exploding bullets while they are incapacitated. According to the fan wiki, the Hedge Maze exit contains a shortcut to the Castle that opens after you enter it for the first time, so the walk gets easier on later runs.

Before pushing on, stock up:

• A full stack of bullets — enemy density in the Dungeon and Castle is high, and running dry mid-ambush is the most common way to lose gear.
• At least one or two repair items (cotton swab, bleach, or repair kit); players in the Steam discussion report guns breaking before the final stretch, and one player there "already died once there and lost all my best gear."
• Cooked food or healing items filling spare inventory space — dinner tables inside the Castle itself also hold cooked food you can eat.
• A charged amulet. Altars appear on the third level of both the Dungeon and the Castle, and NPCs like the Gravedigger can charge it for gold before you leave the church.

Loadout that works here

The Dungeon and Castle are a difficulty spike over previous areas. Players in the game's Steam discussion converge on a consistent setup:

• A shotgun with a penetration enchant like Holy Fire, or a weapon converted into a shotgun — one-shotting the assassins before they reach you matters more than anything else.
• Alternatively, an accurate rifle with a hunter or sniper scope: the Dungeon and Castle have long sightlines where you can pick enemies off before they close in. Pair it with an SMG or shotgun as a secondary for when groups swarm you.
• Sulfur grenades clear swarms when you cannot retreat, and they are also cheap to craft from metal scrap and a false sulfur cap.
• Jump-enhancing gear such as Sulf Air shoes (+1 jump) makes the Dungeon's wooden-platform traversal far easier.

The Dungeon before the Castle

Four levels, amulet altar on the third. Expect gunmen and cultist assassins that leap at you for heavy damage — kill assassins on sight. Enemies ambush in groups and wait in side rooms, so the reliable play (echoed by the Steam players above) is to clear each group fully before entering a side room, and to look for missed platforms when you lose the path. More enemies usually means you are heading the right way.

You may find the Drawer, a storage upgrade for the church — but it eats a lot of inventory space, which this area punishes. Either skip it on your first run or use the amulet to bank it immediately.

The final level holds the executioner mini-boss. Focus the cone on its head while avoiding its weapon; exploding bullets work well. Break the cone, shoot the shining orb inside until the boss stops moving, then step back — it explodes shortly after, and the path to the Castle opens.

The Castle itself

The Castle has four levels with the amulet altar on the third. Alongside the Dungeon's gunmen and assassins you now face:

• Mine cultists — they drop mines everywhere. If you hear a mine nearby, shoot it from range to detonate it safely.
• Laser cultists — they fire a deadly laser; let them finish reloading before you commit to an attack.
• Robotic enemies with powerful steam-venting guns.
• Assassins — same rule as the Dungeon: delete them first.

The route to each golden gate is heavily guarded, but the area compensates with frequent item drops and cooked food on dinner tables. Explore around the bookshelves when the path is unclear, keep moving, and repair weapons between levels. Several vendors can spawn here, including the Blond Magus (a scroll seller) and the DH 'Ell Guy — worth checking if your enchants need work.

Saint Lucia boss fight

Saint Lucia waits in the throne room on the final level. The fight, in order:

1. Open on the threads

   Wait until she moves to the middle of the stage and spreads her threads, then start dealing damage.

2. Kill the assassins fast

   She summons cultist assassins into the arena early. Explosives and mines are extremely effective here — clear them before returning to Lucia.

3. Survive the ghosts

   Ghosts will hit you briefly before returning to her. Keep shooting through it.

4. The dark phase

   When the castle goes dark, immediately shoot the projectiles that appear in the darkness. Shoot them in time and Lucia catches fire; miss and you burn instead.

5. Second wave at 50%

   At half health she summons assassins again. At 40% she darkens the castle a second time.

6. Finish her

   For the remainder she stays in the middle with her threads spread, attacking with screams. Out-damage her before your healing runs out — a path to the Forest opens on her death.

Next steps

• Our SULFUR caves guide covers the best early farming route — useful for rebuilding gear and coins if you die in the Dungeon.
• The SULFUR town guide explains mask enemies and the railgun arena that lead into the Sewers on the way here.

FAQ

Do I need to clear the Hedge Maze every time I want to enter the Castle?

No. Players report the Hedge Maze exit contains a shortcut to the Castle that unlocks after you enter it once, so repeat visits skip the maze.

What is the best weapon setup for the Castle area?

Steam players recommend a shotgun with a penetration enchant (Holy Fire) to one-shot assassins, or a scoped rifle for the long sightlines, with an SMG or shotgun secondary and sulfur grenades for swarms. Bring repair kits — guns break before the end.

How do I avoid the fire attack when the castle goes dark?

As soon as the castle darkens during the Saint Lucia fight, shoot the projectiles appearing in the middle of the darkness immediately. Destroying them sets Lucia on fire; failing sets you on fire.

Is the Castle boss harder than the Dungeon leading to it?

Players on the Steam forums report the opposite: one player who cleared the Dungeon for the first time said the "boss was so easy compared to the rest of the level." The mob density is the real threat, not Lucia herself.

Check note: route and boss details come from the Into Indie Games SULFUR walkthrough, area entry and vendor facts from the fan wiki, and loadout tips from first-hand posts in the Steam community discussion. Version and release facts come from the official Steam page, checked 2026-11-06. Exact enemy health values and drop rates remain unconfirmed by any source used here.