The Atomic Sword is one of the strongest endgame weapons in Sailor Piece, and acquiring it requires substantial dedication. This weapon arrived in Update 7.0 during the major March 2026 update, drawing inspiration from Cid Kagenou in The Eminence in Shadow anime. Its area-of-effect moveset delivers devastating damage across all difficulty tiers, with the fully upgraded F move capable of dealing 1.7 billion damage. The grind demands patience, but the results justify the effort.
Where do you find the Atomic Sword NPC?
An unnamed NPC on Lawless Island sells the sword—one of the later Portal locations you'll unlock. After arriving via portal, follow the path toward the island's corner. You'll pass the Atomic Master NPC first, but that's not your destination. Continue along the outer perimeter until you spot a second NPC with a similar appearance but no floating name tag. That's your seller.
This NPC displays the complete requirement list before allowing any transaction. Nothing about this exchange comes cheap.
Atomic NPC on Lawless Island
What do you need to unlock the Atomic Sword?
The complete requirement list breaks down as follows:
- Eminence Incarnate Title (equipped)
- Shadow Sword (in inventory)
- 45,000 Gems
- 1x Atomic Omen
- 3x Eminence Essence
- 9x Shadow Remnant
- 16x Magic Shard
- 80x Abyss Sigil
Abyss Sigils stand as the only material not sourced from the Atomic boss. All other items—the Eminence Incarnate Title, Atomic Omen, Eminence Essence, Shadow Remnant, and Magic Shard—drop exclusively from that encounter.
How to farm the Atomic boss efficiently
Spawning the Atomic (Cid) boss requires speaking with the Atomic Boss Summoner at Lawless Island's center. Difficulty selection happens before spawn, with Sigil costs scaling accordingly.
| Difficulty | Abyss Sigils Required | Eminence Incarnate Title Drop Rate |
|---|---|---|
| Normal | 1 | 0.7% |
| Medium | 2 | 0.95% |
| Hard | 3 | 1.15% |
| Extreme | 4 | 1.35% |
Normal difficulty presents an Atomic boss with 2,000,000,000 health. Elevated difficulties demand more Sigils but increase drop rates on rarer materials. The Eminence Incarnate Title specifically sees nearly double the drop chance on Extreme compared to Normal.
Normal difficulty drop rates for all Atomic boss materials:
- Magic Shard: 13.75%
- Shadow Remnant: 4.50%
- Atomic Outfit: 1.19%
- Eminence Essence: 1.11%
- Eminence Incarnate Title: 0.7%
- Atomic Omen: 0.4%
One effective strategy: position yourself near Arena Fighter mobs during boss encounters. This approach lets you farm Abyss Sigils from mobs while simultaneously battling the boss, maintaining steady Sigil reserves.
Atomic boss difficulty selection
How do you get Abyss Sigils?
Abyss Sigils drop from two enemy categories: Ninja enemies on Ninja Island and Arena Fighter enemies on Lawless Island. Drop rates stay low, making Luck stacking through Titles, Spec Passives, and related mechanics the most efficient acceleration method. Accepting quests from Quest NPCs before engaging these enemies adds Money and EXP rewards, so don't bypass that interaction.
The sword purchase alone consumes 80 Sigils, with additional Sigils required for each boss spawn throughout your farming sessions. Plan your Sigil budget carefully.
How to get the Shadow Sword
The Shadow Sword (alternatively called Cid V1) serves as a mandatory prerequisite for the Atomic Sword and carries its own distinct grind. Travel to Dungeon Island and locate the Shadow NPC positioned atop the building. Shadow Sword acquisition demands:
- Shadowborn Race
- 10,000,000 Money
- 15,000 Gems
- 1x Atomic Core
- 4x Shadow Essence
- 8x Void Seeds
- 20x Umbral Capsules
Shadowborn Race remains accessible to all players but requires a Race Reroll, which operates on RNG mechanics. Remaining materials originate from the Shadow Dungeon, accessed through the Dungeon Master NPC. Epic and Legendary Chests from powerful enemies on Lawless and Ninja Island frequently contain valuable drops during this phase.
How to unlock the Atomic Sword F move
After obtaining the sword, head to the left end corner of Lawless Island and speak with the Atomic Master NPC to begin the Mastery questline. Three quests require completion:
- Kill the Atomic boss 20 times on Hard or Extreme difficulty (demands at least 60 Abyss Sigils for Hard)
- Obtain the Eminence Clan (acquire Clan Rerolls from enemy drops, boss kills, or Sailor Piece codes)
- Reach Floor 51 in the Infinite Tower 5 times (access via Tower Island's Infinite Tower Portal)
Can you skip the grind and buy it directly?
Yes. The in-game Shop offers a bundle containing exclusively the Atomic Sword for 1,449 Robux. Larger bundles also feature weapons like the Abyssal Empress Sword. Shop purchases bypass all material requirements entirely, though the Mastery questline still needs completion to unlock the F move.
For everything else in Sailor Piece, browse more guides on GAMES.GG to keep your progression moving. The complete breakdown of requirements and drop rates receives thorough coverage in additional detailed guides available for this weapon system.
