Get All Demon Slayer Swords in Reign Piece (June 2026 Guide)
The Demon Slayer update in Reign Piece introduced three powerful swords inspired by popular anime characters, each requiring specific bosses, materials, and raid content. All Demon Slayer sword NPCs are located on Tengen’s Hideout Island, and you’ll need the Infinity Castle Key to access the raid where most materials drop. These weapons offer exceptional damage and smooth animations, becoming some of the strongest weapons when combined with advanced Haki stages.
Quick Reference: All Demon Slayer Swords
| Sword | Required Materials | Boss Location | Special Requirements |
|---|---|---|---|
| Zenitsu | 12 Thunder Breathing Cores, 3 Static Soul Orbs | Zenitsu Boss (crystal spawn) | Sleepwalker Trait |
| Kaigaku | 15 Black Lightning Cores, 1 Demon Blood | Kaigaku (Infinity Castle Raid) | Hybrid Race |
| Tengen Uzui | 20 Flash Sigils, 10 Explosive Rhythm Fragments, 2 Uzui Clan Relics | Tengen Boss (Infinity Castle Raid) | None |
Tengen’s Hideout Island
Before attempting to unlock any Demon Slayer sword, you must access Tengen’s Hideout Island. This island serves as the main hub for all Demon Slayer-related content, including weapon sellers and progression paths. Make sure you’re comfortable fighting mid-to-late-game bosses before attempting this content, as it’s not beginner-friendly.
Contents
The island features all the necessary NPCs for sword progression, material crafting, and raid preparation. Most players recommend reaching at least level 500+ before seriously attempting Demon Slayer content, though skilled players can start earlier with proper preparation.
Infinity Castle Key: Your Gateway to Endgame Content
The Infinity Castle Key is essential for accessing the Infinity Castle Raid, where you’ll obtain materials for Kaigaku and Tengen swords. You have two methods to acquire this key:
Method 1: Random Drops from Zenitsu Boss
The Zenitsu Boss has a chance to drop the full Infinity Castle Key. This method is entirely luck-based but can save you significant crafting time. Many players report getting the key after 10-15 Zenitsu Boss runs, though some get lucky on their first attempt.
Method 2: Crafting at Shibuya Crossing Island
The more reliable method involves crafting the key using fragments. You’ll need to collect Infinity Castle Key Fragments (also dropped by Zenitsu Boss) and craft the complete key at Shibuya Crossing Island. This method requires more grinding but guarantees progression.
Pro Tip: Farm the Zenitsu Boss until you secure at least one Infinity Castle Key before moving to other swords. This saves time and ensures you can access the raid when needed.
Zenitsu Sword: Your First Demon Slayer Weapon
The Zenitsu sword typically serves as your introduction to the Demon Slayer weapon system. It’s the most accessible and provides materials needed for later progression.
Requirements:
- 12 Thunder Breathing Cores
- 3 Static Soul Orbs
- Sleepwalker Trait
How to Obtain:
All required materials drop exclusively from the Zenitsu Boss, which you can spawn using crystals. The boss fight requires strategy and preparation, as drops aren’t guaranteed every run.
Farming Strategy:
- Bring friends for faster kills and increased drop chances
- Focus on learning the boss’s attack patterns to minimize deaths
- Expect to spend 3-4 hours farming for complete materials
- The boss can also drop Infinity Castle Key Fragments, making this dual-purpose farming
The Zenitsu sword features lightning-fast attacks and excellent combo potential, making it ideal for players who prefer aggressive playstyles.
Kaigaku Sword: Darkness and Power
Once you have access to the Infinity Castle Raid, you can pursue the Kaigaku sword, which offers devastating power at the cost of higher requirements.
Requirements:
- 15 Black Lightning Cores
- 1 Demon Blood
- Hybrid Race (must be unlocked beforehand)
How to Obtain:
These materials drop from Kaigaku inside the Infinity Castle Raid. The Hybrid Race requirement is crucial – you must have this race already unlocked before attempting to claim the sword.
Raid Strategy:
- The Infinity Castle Raid features a one-life mechanic – death ends the run
- Bring a balanced team of 3-4 players for best results
- Learn Kaigaku’s attack patterns to avoid unnecessary deaths
- Focus on survival over speed – one mistake can cost you the entire run
The Kaigaku sword delivers massive damage with dark lightning effects, making it excellent for boss fights and raid content.
Tengen Uzui Sword: Flashy and Formidable
The Tengen Uzui sword represents the pinnacle of Demon Slayer weapons, offering impressive visual effects and powerful combat abilities.
Requirements:
- 20 Flash Sigils
- 10 Explosive Rhythm Fragments
- 2 Uzui Clan Relics
How to Obtain:
All required items drop from Tengen Boss fights inside the Infinity Castle Raid. This sword typically takes the longest to farm due to the sheer volume of materials needed.
Advanced Farming Tips:
- Don’t attempt solo unless you’re extremely confident in your abilities
- Focus on one material type at a time to avoid inventory confusion
- Save your Infinity Castle Keys for well-prepared runs
- Consider using damage-boosting items to speed up boss kills
The Tengen sword features dual cleavers with explosive effects and sound-based attacks, making it one of the most visually impressive weapons in the game.
Haki Progression: Maximizing Your Sword Potential
Demon Slayer swords reach their full potential when combined with advanced Haki stages. Here’s how to progress through the Haki system:
Haki Stage One
- Location: Sakura Island
- Method: Purchase from the Haki NPC using in-game currency
- Benefits: Basic damage and defense boosts
Haki Stage Two
- Location: Sanctuary
- Method: Complete quests for the Stage Two Haki NPC
- Requirements: Farm bosses for Haki fragments and orbs
- Benefits: Significant combat enhancement
Haki V3 (Maximum Power)
- Step 1: Visit Prism Pillar and interact with the NPC
- Step 2: Craft Pressure Cores and Shard of Dominance at Shibuya Crossing Island
- Step 3: Travel to Tengen’s Hideout Island, enter Mysterious Moss Temple, and interact with the chamber
- Benefits: Massive damage output, improved survivability, and enhanced raid performance
Pro Tip: Unlock Haki V3 before attempting difficult Demon Slayer content. The power difference is substantial and can make challenging fights much more manageable.
Advanced Farming Strategies
After dozens of hours with Demon Slayer content, here are the most effective strategies:
Team Composition Matters
The Infinity Castle Raid is nearly impossible solo. Find reliable teammates with complementary abilities. Ideal teams include:
- 1 Tank/Damage absorber
- 2 Damage dealers
- 1 Support/Healer (if available)
Resource Management
- Save Infinity Castle Keys for well-prepared runs
- Don’t waste crystals on poorly planned boss attempts
- Keep backup materials to avoid progression stalls
Boss Pattern Mastery
Each boss has specific tells and attack patterns:
- Zenitsu: Watch for lightning charge animations
- Kaigaku: Learn to dodge his dark lightning sweeps
- Tengen: Anticipate his explosive rhythm attacks
Inventory Optimization
- Focus on one sword at a time to avoid confusion
- Use storage for excess materials
- Keep essential items readily accessible
Community Resources and Official Links
Join the community to stay updated and find help with difficult content:
- Official Discord Server: Connect with experienced players for raid groups and tips
- Official Trello Board: Access the latest updates and patch notes
- Reddit Community: Share experiences and learn from other players
- YouTube Guides: Visual demonstrations of boss fights and strategies
These resources provide real-time updates, community support, and exclusive insights that can significantly improve your Demon Slayer sword progression.
Frequently Asked Questions
Q: Are Demon Slayer swords worth the grind?
A: Absolutely! These are among the strongest weapons in Reign Piece 2026, especially when combined with advanced Haki stages. They excel in both raids and boss fights, making them essential for endgame content.
Q: Can I get these swords solo?
A: While technically possible, solo play is extremely difficult due to the Infinity Castle Raid’s one-life mechanic. Most players recommend teams of 3-4 for optimal success rates.
Q: Do I need to complete the swords in order?
A: Not strictly required, but the Zenitsu sword is the most accessible and provides Infinity Castle Keys, making it the logical starting point for progression.
Q: Will these swords get outdated in future updates?
A: The Demon Slayer swords are designed to be endgame-viable for the foreseeable future. While future updates may bring stronger weapons, these will remain competitive choices.
Q: How long does it take to get all swords?
A: For most players, completing all three swords takes 20-40 hours of dedicated farming, depending on team composition, luck with drops, and preparation level.
Q: What’s the best race for Demon Slayer swords?
A: Hybrid Race is required for the Kaigaku sword, but other swords work well with any race. Focus on the race that complements your playstyle.
Conclusion
Getting all Demon Slayer swords in Reign Piece represents one of the most rewarding progression paths available in 2026. From the thrill of defeating the Zenitsu Boss to the satisfaction of mastering the Infinity Castle Raid, each step provides meaningful advancement and powerful rewards.
Remember to take your time, farm smart, and don’t hesitate to seek help from the community. These swords aren’t just powerful weapons – they’re trophies that showcase your dedication and skill as a Reign Piece player.
Whether you’re aiming for competitive raid performance or simply want to collect these iconic blades, the Demon Slayer swords offer something for every type of player. Start with the Zenitsu sword, progress through the Haki stages, and work your way up to the prestigious Tengen Uzui sword.
Call to Action: Bookmark this guide and check back regularly for updates! The Demon Slayer content continues to evolve with balance changes and new strategies. Join the official Discord community to find raid groups and share your progression journey with fellow players.
