In Castlevania: Belmont’s Curse, Arcana 13 is The Brittle King, a card that’s easy to overlook. Its only clue leads to Arthur, the boss who appears after you solve a small puzzle involving a sword embedded in stone. Though the puzzle may seem to test your stats, it doesn’t. The outcome depends on which Arcana Rose has equipped when she makes contact with the sword.
Quick answer: Go to the Chapel in Notre-Dame, on the east side past the East Gallery. Equip the Fist of Talos spell, interact with the sword in the stone, and defeat Arthur.
The Brittle King requirements
Your character level, stat totals, and number of sealed Arcanas have no effect on whether the sword opens. These are the only things you need:
- Notre-Dame becomes available once The Builder, The Occultist, and The Artist are complete; afterward, use Brauner’s Paintbrush on the magical painting in the Main Hall.
- Defeat Talos during The Builder to obtain the Fist of Talos spell.
- Double Jump, which you get after defeating Death in Notre-Dame’s Choir.
Notre-Dame is locked behind The Builder, so you will always have Fist of Talos by the time you reach the sword. You don’t need to backtrack for it.
Where to find the Brittle King: The Chapel in Notre-Dame
Arthur is the boss of the Chapel. It sits on the right-hand side of the Notre-Dame map, close to the East Gallery Mirror of Life. You can’t cross the East Gallery without a second jump, so beat Death first.
How to solve the sword in the stone puzzle
Excalibur’s inscription demands a “feat of strength.” It calls the person able to pull the blade a titan, a colossus, and a giant; each term indicates Talos. As you approach, your Tarot deck provides a clue. A yellow glow rather than a red one means the correct card is equipped. The game first introduces this Arcanic Resonance signal through Brauner’s Notre-Dame painting.
Fists of Talos, the Masterpiece-rarity glove weapon from the Clock Tower, is a different item, and equipping it does nothing at the sword. You need the spell.
Arthur boss stats and immunities
| Stat | Value |
|---|---|
| Health | 11000 |
| Attack | 55 |
| XP | 500 |
| Location | Notre-Dame, Chapel |
| Arcana card |  The Brittle King |
Arthur is immune to bleed, burn, freeze, petrify, slam down, and being launched into the air. He also ignores the slow from Chronomantic Dive, the link from Freezing Path, and the launch from Infernal Pyre. Status-effect builds won’t help much here, so plan on dealing straight damage.
How to defeat Arthur, the Brittle King
Arthur takes the form of an enormous stained-glass knight carrying a sword and shield, with a limited moveset. Expect sweeping melee strikes, shield bashes, and overhead beams of light. His damage varies with when you challenge him. Taking him on immediately after The Shadow or The Miser means one blow may remove over half of Rose’s maximum health. A few more health upgrades, levels, and stronger Relics make the fight much easier. The Mirror of Life is nearby if you fall, keeping the return trip short.
Phase one: Get behind the shield
Arthur’s shield blocks all damage, even hits to its edges. When he raises it, use the luminous anchors above the arena to swing over him with the Arcane Whip and attack his back. When he turns around, grapple back up and switch sides again. Keep this up and the first half of his health bar goes down fast.
For maximum damage, launch Rose with an upward strike and follow with repeated downward attacks. Each blow extends her airtime slightly, letting you land five or more hits before she drops.
Phase two: Light rays at 50% health
When Arthur drops to 50% health, he lifts his shield toward the ceiling. He catches the light coming down and reflects it across the arena as beams. Stay out of the beams, because they heat up and burn Rose at regular intervals. While he’s charging them, getting close is too risky.
Use ranged attacks during this part. Holy Cross, the spell Leon drops, throws a cross that comes back to Rose and does more damage the farther it travels from her. When Arthur starts moving the beams around, you get a short opening. Rush in and attack, then back off when the beams come your way again.
Weapons for the Arthur fight
| Weapon | Attack power | Rarity / tier | Found in |
|---|---|---|---|
 Vampire Killer | 40 | Legendary / 4 | Notre-Dame |
 Whip | 24 | Ordinary / 1 | Catacombs of Paris |
Whips are a good fit here. Both deal extra damage at the far end of their reach, and Arthur is so big that you can hit him with the tip while staying outside his close-range swings.
Vampire Killer is the better choice of the two. Trevor Belmont gives it to Rose after Death falls. Its tip burns enemies, but that part won’t work on Arthur because he’s immune to burn. You still get the higher base damage.
Whip is the basic version from the Catacombs of Paris. It has the same tip bonus and the same Whip Drag finisher. Use it if you haven’t switched to Vampire Killer yet.
Brittle King rewards: Excalibur and Stained-Glass Shield
Here’s how you know the card is done. Arthur breaks into glass on the Chapel floor and leaves a glowing golden orb, which Rose absorbs. A stained-glass Tarot screen then shows The Brittle King and grants Stained-Glass Shield. A second screen awards Excalibur. The card is now marked complete, and Excalibur goes directly into your inventory, so you don’t need to go back to the stone.
Excalibur
| Stat | Value |
|---|---|
| Weapon type | Two-handed sword |
| Rarity / tier | Legendary / 4 |
| ATK | 100 |
| Attack power | 44 |
| Stagger power | 30 |
| Mana per hit | 5 |
| Combo finisher | Blade Dive |
Excalibur fires bolts of light when it attacks, so it can hit enemies from a distance. If you hold the attack button and then release it, it does a charged strike that hits harder.
Stained-Glass Shield
Stained-Glass Shield is a defensive spell. It costs 100 mana and has 30 attack power. It surrounds Rose with a magic barrier. When the barrier blocks a hit, she takes no damage, isn’t interrupted, and doesn’t get any status effects from that attack. Shards of glass also fly at nearby enemies. You can unlock three gifts to make it stronger:
- The barrier can absorb one more attack before it breaks.
- Every time Rose takes damage, with or without the barrier up, a glass shard fires at the nearest enemy.
- If Rose is hit in the middle of an attack, the damage is cut by 50% and her attack keeps going.
The Brittle King Works of Mercy
The card also has three Works of Mercy. You can work on them over the rest of your run once Stained-Glass Shield is equipped:
- When an incoming attack would be fatal, use Arthur’s spell to absorb it.
- Kill 25 Haunted Armor.
- Kill 3 enemies with a single attack.
The first one is the trickiest. Keep the shield up during risky fights so that a hit that would have finished Rose gets absorbed instead. The other two will mostly happen as you keep exploring Notre-Dame and the rest of Dracula’s Castle.
