How to Get Phantasm Core in Sailor Piece - Gilgamesh Boss Guide (0.5-0.75% Drop Rate)
Complete guide to farming the Phantasm Core from the King of Heroes (Gilgamesh) boss in Sailor Piece. Learn the 0.5-0.75% drop rate strategy, team requirements, and how to craft the Babylon Key for the King of Heroes F Move. Updated April 2026.
💡 Quick Tip: You need 2 Phantasm Cores for the Babylon Key. At 0.5-0.75% drop rate, expect 100-200 kills per core. Team up with strong players.
👑Phantasm Core Overview & Drop Rate Analysis
| Property | Details | SEO Notes |
|---|---|---|
| Item | Phantasm Core | Mythical-rarity boss drop |
| Rarity | Mythical | Highest rarity tier in Sailor Piece |
| Drop Source | King of Heroes (Gilgamesh) boss | Boss Island summon-only boss |
| Drop Rate | 0.5% - 0.75% | One of the lowest drop rates in the game |
| Location | Boss Island — Boss Summoner NPC | Requires Divine Grail to summon |
| Tradeable | No — must farm it yourself | Cannot be traded, must be farmed |
| Primary Use | Craft Babylon Key (F Move unlock) | Unlocks King of Heroes F Move |
| Required for | Ascension 8, King of Heroes F Move | Endgame progression requirement |
The Phantasm Core is required for Ascension 8 (2 cores needed) and the King of Heroes F Move (2 cores for Babylon Key). You need 4 cores total for full endgame progression.
⚔️How to Summon Gilgamesh (King of Heroes)
- Travel to Boss Island via the world map portal
- Find the Boss Summoner NPC on Boss Island
- Select King of Heroes (Gilgamesh) from the boss list
- Pay the summoning cost: 1 Divine Grail + 500,000 Beli + 500 Gems
- The boss spawns in the arena — fight begins immediately
⚠️ Gilgamesh is one of the toughest bosses. Do not attempt solo unless you have endgame gear (level 75+, S-tier sword, good race/clan).
🎯Boss Fight Strategy
Gilgamesh hits hard and has a massive HP pool. The key to farming him efficiently is teamwork and proper builds.
Recommended Level
75+ minimum. Higher is better for consistent damage output.
Best Race
Servant (+75% HP, +67% DMG, lifesteal) or Sunborn (+70% HP, sword DMG boost).
Best Clan
Voldigoat (25% more DMG to NPCs below 50% HP) for faster kills.
Best Sword
Bisento or Yoru (S-tier DPS). Ice Queen Sword also works well.
The 10% damage threshold is critical. If you don't deal enough damage, you get zero loot. In a 3-player team, each person needs to contribute meaningfully.
📊Drop Rate Math
At 0.5-0.75% drop rate, here's what to expect statistically:
| Kills | Chance of Getting at Least 1 Core |
|---|---|
| 10 | ~5-7% |
| 50 | ~22-31% |
| 100 | ~39-53% |
| 200 | ~63-78% |
| 300 | ~78-90% |
| 500 | ~92-98% |
Expect 100-200 kills on average. At 3-5 minutes per kill with a good team, that's 5-17 hours of farming.
🔑Crafting the Babylon Key
The Phantasm Core's primary use is crafting the Babylon Key, which unlocks the King of Heroes F Move — a powerful special attack with a +30% damage buff.
| Material | Quantity | Source |
|---|---|---|
| Phantasm Core | 2 | Gilgamesh boss (0.5-0.75%) |
| Broken Sword | 100 | Various bosses |
| Golden Essence | 5 | Boss drops |
| Servant Race | Required | Race reroll (0.1% chance) |
⚠️ You need the Servant Race equipped to interact with the Babylon Key Crafter NPC. If you don't have Servant, you'll need to reroll for it first.
- Collect 2 Phantasm Cores from Gilgamesh
- Farm 100 Broken Swords from various bosses
- Obtain 5 Golden Essence from boss drops
- Equip the Servant Race
- Visit the Babylon Key Crafter NPC on Boss Island
- Craft the key and use it from your inventory to unlock the F Move
❓ Frequently Asked Questions
How do I get the Phantasm Core in Sailor Piece?
Defeat the King of Heroes (Gilgamesh) boss on Boss Island. The Phantasm Core has a 0.5-0.75% drop rate per kill. You must deal at least 10% of the boss's HP to qualify for drops.
Can I trade for a Phantasm Core?
No, the Phantasm Core is not tradeable. You must farm it directly from the Gilgamesh boss.
What is the Phantasm Core used for?
It's used to craft the Babylon Key, which unlocks the King of Heroes F Move — a special attack that also gives a +30% damage buff.
How many Phantasm Cores do I need?
You need 2 Phantasm Cores to craft the Babylon Key. At 0.5-0.75% drop rate, expect significant farming time.
What's the best strategy for farming Gilgamesh?
Team up with 2-3 strong players (level 75+). Use Servant or Sunborn race, Voldigoat clan, and an S-tier sword. Each player must deal at least 10% of the boss's HP.