- What to know
- Why you must start with the Sung Jinwoo Sword
- Materials required from the Double Dungeon
- Where the upgrade happens on Dungeon Island
- How to complete the Double Dungeon efficiently
- Shadow Monarch Sword showcase and combat performance
- Rewards summary from the Double Dungeon grind
- Is the Shadow Monarch Sword worth the grind?
What to know
- The Shadow Monarch Sword is an upgraded endgame weapon in Sailor Piece.
- You must already own the Sung Jinwoo Sword before starting the upgrade process.
- All required materials drop inside the Double Dungeon instance.
- The final exchange happens at Dungeon Island through the Shadow Monarch NPC.
The Shadow Monarch Sword is one of the most sought-after weapons in Sailor Piece due to its strong scaling, dark-themed abilities, and high burst damage potential. If you are aiming to transition into late-game PvE or want a competitive edge in boss raids, this weapon becomes a clear milestone. The process is straightforward in structure but demanding in execution, as every required material comes from challenging dungeon content.
| Category | Details |
|---|---|
| Weapon Name | Shadow Monarch Sword |
| Base Requirement | Sung Jinwoo Sword |
| Upgrade Materials | Shadow Crystal, Kamish Daggers, Monarch Essences, Monarch Cores, King of Shadows Title |
| Material Source | Double Dungeon |
| Exchange Location | Dungeon Island |
| NPC Required | Shadow Monarch NPC |
| Difficulty Level | High (Dungeon-based farming) |
| Primary Use | High-damage PvE and boss fights |
The Shadow Monarch Sword is not obtainable through random rolls or fruit dealers. Instead, it is a structured progression reward tied directly to dungeon completion and material grinding.
Why you must start with the Sung Jinwoo Sword
Before attempting anything else, you must already possess the Sung Jinwoo Sword. Without it, the Shadow Monarch NPC will not offer the exchange option. The Sung Jinwoo Sword acts as the base weapon that evolves into the Shadow Monarch variant. If you do not have it yet, your priority should be completing the content chain that rewards that weapon first.

The game checks your inventory when interacting with the Shadow Monarch NPC. If the base sword is missing, the upgrade dialogue will not trigger. This ensures that only players who have progressed through the proper storyline and combat stages can obtain the final weapon.
Materials required from the Double Dungeon
All upgrade components drop exclusively inside the Double Dungeon. This means you will be running the dungeon multiple times depending on your drop luck and party efficiency.
| Required Material | Quantity Needed | Source |
|---|---|---|
| Shadow Crystal | 1 | Double Dungeon Boss Drop |
| Kamish Dagger | 2 | Double Dungeon Elite/Boss Drop |
| Monarch Essence | 5 | Dungeon Enemies & Mini Bosses |
| Monarch Core | 10 | Dungeon Enemy Drops |
| King of Shadows Title | 1 | Double Dungeon Completion Reward |
The Shadow Crystal is typically the rarest component. It usually drops from the final boss inside the Double Dungeon and may require several clears depending on RNG. The Kamish Daggers also drop from higher-tier enemies within the dungeon and are not guaranteed per run.

The Monarch Essences and Monarch Cores are more common but still require consistent farming. Monarch Cores tend to drop from regular enemies, while Essences often come from mini-boss encounters.
The King of Shadows title is earned by completing the Double Dungeon under its required conditions. If you fail or leave early, you will not receive the title reward.
Where the upgrade happens on Dungeon Island
After collecting every required item, you must travel to Dungeon Island. This island serves as the central hub for dungeon-related progression in Sailor Piece. The Shadow Monarch NPC is located near the dungeon-related structures, typically close to the main interaction area tied to advanced content.

When you interact with the NPC, the game checks your inventory for all required materials and the Sung Jinwoo Sword. If everything is present, the NPC offers the exchange option. Confirming the dialogue consumes all listed materials and permanently upgrades your weapon into the Shadow Monarch Sword.
There is no additional boss fight at the exchange stage. The difficulty lies entirely in the material grind.
How to complete the Double Dungeon efficiently
Step 1
Enter the Double Dungeon with a balanced build. Prioritize survivability and burst damage. The dungeon contains multiple waves of enemies followed by mini-boss encounters and a final boss fight.

Step 2
Clear regular mobs methodically to farm Monarch Cores. These drop frequently but not guaranteed. Staying alive and clearing efficiently improves your farming rate per run.
Step 3
Defeat mini-boss enemies to increase your chances of obtaining Monarch Essences and possibly Kamish Daggers. Coordinate cooldown usage if you are in a party.
Step 4
Engage the final boss carefully. This boss is your primary source for the Shadow Crystal and additional high-tier drops. Learn its attack patterns to minimize potion usage and avoid unnecessary wipes.
Step 5
Complete the dungeon fully to secure the King of Shadows title. Partial clears do not count. Make sure the completion message triggers before leaving.
Step 6
Repeat the dungeon until you meet all quantity requirements. Because some drops are RNG-based, multiple clears are typically required.

Shadow Monarch Sword showcase and combat performance
Once obtained, the Shadow Monarch Sword offers significantly improved damage output compared to the Sung Jinwoo Sword. Its scaling is optimized for high-level players, making it particularly effective in boss raids and advanced dungeon content.
In combat, you will notice stronger skill effects, enhanced burst potential, and faster enemy clear times. The weapon is especially useful against high-health targets due to its improved base damage and ability synergy. Players who focus on aggressive melee builds will benefit most from its scaling.

In PvE scenarios, the weapon drastically reduces time-to-kill against dungeon bosses. In competitive situations, it provides a noticeable damage advantage over mid-tier swords, though player skill and build optimization still matter.
Rewards summary from the Double Dungeon grind
| Reward Type | Purpose |
|---|---|
| Monarch Core | Upgrade Material |
| Monarch Essence | Upgrade Material |
| Kamish Dagger | Upgrade Material |
| Shadow Crystal | Final Upgrade Component |
| King of Shadows Title | Required for Exchange |
Each run contributes toward your upgrade goal. Even if you do not receive a rare drop, you are still progressing toward the total required counts.
Is the Shadow Monarch Sword worth the grind?
For players aiming at endgame content in Sailor Piece, the answer is yes. The weapon is positioned as a progression milestone rather than a cosmetic upgrade. Its damage output, synergy potential, and exclusivity make it a strong long-term investment.
If you are actively clearing the Double Dungeon anyway, farming toward this weapon becomes a natural next step in your build progression.