Deep within the heart of Maple Isle, a malevolent power once sealed for centuries has begun to stir. The ancient Oni King, Shuten-dōji, long imprisoned beneath sacred wards, has awakened. Time and turmoil have fractured the seal, birthing a bottomless rift that spills forth a sinister miasma — a toxic blend of demonic aura and corrupted energy.
From this abyss, the land itself twists under dark influence. Monsters mutate, the Blood Moon rises, and the once-peaceful isle descends into chaos. The whispers in the mist tell of Shuten-dōji’s return — and with it, the beginning of the Sealed Island Calamity.
Dark War Survival Sealed Island Guide
Dark War Survival: Sealed Island is a large-scale seasonal event that combines territory capture, alliance strategy, and escalating survival challenges under the Blood Moon’s curse. Your objective is to:
- Secure Soulstones from captured territories.
- Build and defend alliance structures.
- Survive the spreading miasma by managing infection and purification.
- Defeat the Oni King to break the final seal.
Each mechanic in this event interlocks, creating a dynamic cycle of expansion, infection control, and high-risk reward.
Soulstone System
Soulstones are the cornerstone of this season’s competition.
- Territory Production: Once your alliance captures a world territory, it automatically begins generating Soulstones over time.
- Season Settlement: When the season ends, alliances are ranked by their total Soulstone count. Higher ranks yield greater seasonal rewards — exclusive items, currencies, and titles.
- Strategic Role: Defending territories with high Soulstone yield is crucial, as losing one near season end can shift rankings dramatically.
Tip: Focus your alliance on securing central and resource-rich zones early. These zones tend to produce more Soulstones and give tactical advantage during Blood Moon escalation.
Blood Moon Shroud
The Blood Moon is the heart of the event’s corruption cycle.
As miasma levels rise, the Blood Moon slowly ascends, enveloping Maple Isle in a crimson haze. The higher the miasma saturation, the more powerful the corrupted monsters become — including unique Blood Moon Bosses that emerge to challenge survivors.
Corrupted Bosses
[Blood Moon] Rotting Oni
A decaying monstrosity whose fury intensifies with each Blood Moon rise. Its attacks spread heavy miasma, infecting troops and fortifications alike.
[Blood Moon] Booze Brute
A maddened giant carrying a massive cask of demonic brew. Under the Blood Moon, its hair blazes red, and its strikes deliver massive area damage.
Defeating these bosses yields Magatama and rare crafting materials — essential for progression in Lan’s Shadow Shop.
Magatama & Lan’s Shadow Shop
Magatama are sacred jade-like artifacts symbolizing soul and life. They function as the seasonal event currency.
You can earn Magatama by:
Defeating Blood Moon bosses.
Completing Blood Moon trials.
Participating in alliance events and Soulstone Scrambles.
Use Magatama in Lan’s Shadow Shop, where the mysterious trader Lan offers rare items and enhancements available only during this event.
Note: All unspent Magatama will be automatically reclaimed after the event ends — make sure to use them before the Blood Moon fades.
Miasma Mechanics
The Miasma System defines the survival aspect of the Sealed Island event. Every battle and exploration increases exposure to the toxic aura, resulting in status debuffs and potential infection.
Key Concepts
- Miasma Infection:
When your troop’s virus resistance is below the target’s infection level, your units risk infection post-battle. - Miasma Zombies:
Certain enemies carry heavy miasma. Fighting them adds miasma stacks regardless of your resistance. - Ally Purification:
Alliance members can help purify infected troops, accelerating recovery and preventing contamination spread. - Miasma Stacks:
Higher stack counts increase debuffs and can weaken your shelter’s defense efficiency. - Miasma Spread:
Victorious but infected troops can carry miasma back to your shelter, contaminating defenses if not purified.
Tip: Rotate healthy troops into front-line fights and assign infected units to recovery queues immediately after combat. Neglecting miasma management will cripple your combat readiness fast.
Alliance Altar & Seasonal Structures
The Alliance Altar is your faction’s central hub on Maple Isle.
It allows members to place personal seasonal buildings within its radius.
It stores Soulstones collected by all members.
It acts as the main objective during Soulstone Scramble phases.
Seasonal Building Resources
Stone: Common material gathered from Maple Isle, used to build Quartz Factories.
Quartz: Produced in Quartz Factories, used for advanced structures like the Oni Seal Hall — crucial for late-season defense and summoning rituals.
Yum Corner Mini-Game
During calmer phases, the Yum Corner event provides a lighter activity:
Match three identical ingredient cards to clear stages.
Each completed stage grants rewards such as resources, purification items, and Magatama.
This mini-event serves as a refreshing break from heavy combat and miasma management.
Float Parade
As the Blood Moon peaks, the Float Parade emerges — a haunting spectacle led by the Kitsune King.
Evil spirits, illuminated by lanterns, drift through Maple Isle in eerie procession. The parade marks the transition toward the Final Call, signaling the Oni King’s imminent descent.
Sacred Tree Blessing
The sacred tree — once a source of protection — now flickers weakly under the Blood Moon.
Players can donate Omamori (amulets of prayer) to restore its light. When the blessing meter is filled, the sacred tree’s seal renews, granting buffs and temporary purification across the alliance.
Omamori can be used in multiple events this season, but they expire once the season ends.
Evil Seal & Shuten-doom
The Evil Seal represents the final stage of corruption.
Here, Shuten-dōji’s soul, now warped into Shuten-doom, manifests in a massive phantom form. His body burns with Blood Moon fire, and every motion unleashes waves of destruction.
Defeating Shuten-doom requires alliance coordination, high purification levels, and optimized troop formations resistant to miasma debuffs.
Trade War & Blood Moon Shop
While the Oni King’s shadow looms, survivors also clash in Trade Wars for dominance over resource lines.
Rubies spent in the market generate tax, which transforms into Golden Bonds once markets refresh. Governors can distribute these as Red Packets — a vital income stream during prolonged wars.
The Blood Moon Shop opens during these phases, selling rare goods in exchange for Magatama.
Soulstone Scramble & Final Call
The final stage of the event — Soulstone Scramble — determines the ultimate fate of Maple Isle.
All alliances race to seize as many Soulstones as possible before the Blood Moon fully ascends.
When the Final Call begins, all seals weaken, bosses go berserk, and Shuten-dōji himself appears to claim dominion.
The alliance that endures and holds the most Soulstones when the Blood Moon fades will be crowned the ruler of Sealed Island.
Dark War Survival: Sealed Island is more than just a seasonal event — it’s a battle for survival, power, and purity under the crimson moon. Managing your miasma exposure, coordinating alliance structures, and timing your attacks against Blood Moon bosses are key to mastering this event.
