The Lava Ore and Lava Key are the two items you need to summon the Mace Boss in Haze Seas, and both are tied to the same spot behind Marine Base Town. One is a free pickup, the other is a rare boss drop, and you need both in your inventory before the summon works.
Quick answer: Pick up the Lava Key from the table near the Marine Base Town spawn, farm the Lava Ore from the Marine Captain (roughly a 5% drop), use the key to open the gate on the cave behind town, then place the Lava Ore in the cauldron inside to spawn the Mace Boss.
What you need before summoning the Mace Boss
Both items work together. The Lava Key unlocks the gate to the cave, and the cave is where the cauldron sits. The Lava Ore goes into that cauldron to trigger the fight. Skipping either one means you cannot start the summon.
| Item | How to get it | What it does |
|---|---|---|
| Lava Key | Free pickup on a wooden table near the Marine Base Town spawn | Unlocks the metal gate on the cave behind Marine Base Town |
| Lava Ore | Rare drop from the Marine Captain boss (about 5%) | Placed in the cauldron inside the cave to spawn the Mace Boss |
Get the Lava Key at Marine Base Town
The Lava Key does not require a boss fight. It sits out in the open close to the spawn and dock area of Marine Base Town, so grab it first before you start grinding for the ore.
Farm the Lava Ore from the Marine Captain
The Lava Ore only comes from the Marine Captain, a boss that spawns in the main courtyard of Marine Base Town. The drop rate sits around 5%, so expect several kills before it appears. This is the slow part of the process.
Tip: Set your spawn point at the Marine Base Town docks. If you go down during the fight, you can run straight back to the courtyard before the boss resets its health.
Open the cave and summon the Mace Boss
With the key and the ore both in your inventory, head to the cave in the rocky cliffs directly behind Marine Base Town. This is where the summon happens.
To earn any of the drops, you must deal at least 20% of the total damage to the Mace Boss during the fight. If your contribution falls below that, you walk away with nothing.
Mace Boss rewards and drop rates
Beating the Mace Boss guarantees both the Mace V1 Sword and the Coded Mask accessory, alongside currency and bounty. The two gear pieces are the reason most players run this fight.
| Reward | Type | Drop chance |
|---|---|---|
| Mace V1 Sword | Weapon | 100% |
| Coded Mask | Accessory | 100% |
| 700 Bounty | Bounty | Guaranteed |
| 15x Gems | Currency | Guaranteed |
| 5,000 coins | Currency | Guaranteed |
The Coded Mask raises your HP by 500 and increases Sword damage by 5% when equipped, which makes it a strong early pickup for survivability. The Mace V1 Sword unlocks two moves as it levels: Earth Crash, a ground slam that hits nearby enemies at Sword Level 50, and Bagua, a forward charge at Sword Level 150.
Once the fight ends and you have met the damage threshold, the drops appear in your inventory and the currency and bounty are added automatically. That confirmation is how you know the summon and clear worked. If nothing drops, the usual cause is dealing under 20% of the boss’s total damage, so bring enough firepower or a coordinated group to hit that share.
