How to Get Slime Core in Sailor Piece

Slime Core is one of the rarest crafting materials in Sailor Piece, required for the Rimuru Sword and Ascension progression. This item only drops from the Demon Lord boss on Slime Island with a very low drop rate. Getting Slime Core requires completing a quest, farming materials, crafting keys, and defeating the boss multiple times. Here's how to get Slime Core in Sailor Piece.

How to Get Slime Shards

Travel to Slime Island through any teleporter on the map. Once you arrive, head to the center of town and look for the Slime Key Crafter NPC. Talk to the Slime Key Crafter and complete his quest. This quest unlocks the ability to craft Slime Keys, which you need to spawn the Demon Lord boss. Without completing this quest first, you cannot progress toward getting Slime Core.

After finishing the quest, you'll find a group of Slime Warriors on this island. Defeat these enemies repeatedly to farm Slime Shards. Each Slime Warrior has a chance to drop a Slime Shard when killed. Farm Slime Warriors until you collect at least 2 Slime Shards. The drop rate isn't guaranteed, so you'll need to kill multiple Slime Warriors before getting enough shards.

How to Craft Slime Key

Return to the Slime Key Crafter NPC in town once you have 2 Slime Shards. Talk to him and select the crafting option. He will combine your 2 Slime Shards into 1 Slime Key. Each Slime Key allows you to spawn the Demon Lord boss one time. If you want to farm Slime Core efficiently, craft multiple Slime Keys before heading to the boss arena.

How to Spawn and Defeat Demon Lord Boss

Head to Slime Island. Look for the Slime Summoner NPC. Talk to this NPC and hand over 1 Slime Key to summon the Demon Lord boss. Defeat the Demon Lord to receive random drops. If it didn't drop, you'll need to farm more Slime Shards, craft another Slime Key, and fight the boss again.

Slime Core Drop Rate and Farming Tips

Slime Core has a 1.18% drop rate from the Demon Lord boss. This extremely low drop rate means you'll likely need to defeat the boss dozens of times before getting a single Slime Core. Farming this material requires patience and consistent grinding.

Farm Slime Warriors in bulk sessions rather than farming 2 shards at a time. Collect 10-20 Slime Shards in one grinding session, craft 5-10 Slime Keys, then run the boss repeatedly. This saves time traveling back and forth between the farming area and boss arena.

Don't get discouraged by bad RNG. Some players get Slime Core on their first few attempts while others need 50+ kills. The drop is entirely random, so keep farming until it drops.

What to Use Slime Core For

Slime Core is required to craft the Rimuru Sword, one of the best weapons in Sailor Piece. Find the Rimuru Sword seller in the back right corner of Slime Island. He requires these materials to craft the sword:

Slime Core is also required for Ascension at the Ascension Merchant on Sailor Island. Ascensions provide massive stat bonuses that significantly boost your character's power. Save any extra Slime Cores you farm for future Ascension requirements. For more guides check out our Sailor Piece wiki.