Nocturnal Sweeping (Mandarin: 深夜清扫) is an event that lasted from March 20th, 12:00 to April 17th, 2025 10:00 (KST). It is released alongside Intervallo V: Nocturnal Sweeping.
During the event period, playing through stages and dungeons will allow the player to earn [Sweeper Fuel Cylinder] that can be then exchanged in the event's reward shop.
Playing through the event-exclusive Stages & Dungeons will award Sweeper Fuel Cylinders, with an additional reward for the first time clear of the stage.
Playing through older Main Story Stages and Dungeons for the first time will award Sweeper Fuel Cylinders based on the amount of Enkephalin consumed.
Clearing a Mirror Dungeon will award 10 Sweeper Fuel Cylinders for each Floor cleared (20 Sweeper Fuel Cylinders in Hard difficulty). During the event period, the 'Nocturnal Sweeping' Floor Pack will always appear on Floor 5 in the Mirror of the Dreaming Hard Difficulty and—if selected—will award additional Sweeper Fuel Cylinders.
If the 'Nocturnal Sweeping' Theme Pack is cleared on Normal Difficulty, it will grant an additional 50 Sweeper Fuel Cylinders upon claiming the reward. If cleared on Hard Difficulty, it will grant an additional 100 Sweeper Fuel Cylinders upon claiming the reward.
Additionally, having the Event Identities in your Team loadout (even when not directly participating in battle) will boost the amount of Sweeper Fuel Cylinders earned from stages and dungeons.
The boost from having multiple Identities is additive and maxes out at a 100% bonus.
The earning boost applies to first-time clear rewards as well as Mirror Dungeon rewards.
Rarely (5%) upon clearing a stage, a [Sweeper Fuel Tank] (which will be automatically converted to 20 Sweeper Fuel Cylinders) will drop. Sweeper Fuel Tanks have the highest chance to drop (10%) upon clearing the final Encounter of the event.
Reward Exchange
The [Reward Exchange] acts as a shop where Sweeper Fuel Cylinders can be exchanged for various rewards.
Rewards could be received from the Reward Exchange for five weeks (March 20th 2025, 12:00 - April 24th 2025, 10:00 KST).
A total of 5350 Sweeper Fuel Cylinders are required to claim all the rewards for this Event.
Item Description
Used to purchase various rewards from the Reward Exchange menu.
These fuel cylinders contain the energy source for the Sweepers, who cleanse the City every Night in the Backstreets. Despite the nightly chaos, people step out each morning to pristine streets on their way to work—all thanks to the Sweepers. Using their fluid fuel, they dissolve anything that doesn't belong in the City, from street litter to unauthorized structures, as they flood the streets at night. Like clockwork, they emerge from the subterranean depths beneath the City every night. I do wonder, though—just how deep do they come from? - Excerpt from an interview with an LCCB Employee
Spawns rarely. Converted to 20 Sweeper Fuel Cylinder immediately upon acquisition.
Much about the Sweepers remains a mystery. When did they first begin their nightly labors? Where do they come from? It is said that the only institution they cooperate with is the Head. The Sweepers’ fluid fuel is a multifunctional resource—it forms their bodies, serves as a weapon to dissolve whatever lies in their path, and sustains them. This is merely a personal curiosity, but I cannot help but wonder how they propagate. Perhaps they are the culprits behind reports of children vanishing during Nights in the Backstreets… or kidnappings from the Outskirts - Excerpt from an interview with an LCCA Employee
[Sweeper Fuel Cylinder] that can be then exchanged in the event's reward shop.
Enkephalin consumed.
[Sweeper Fuel Tank] (which will be automatically converted to 20 
Nocturnal Sweeping - Special Ticket Customization
Decorative Banner #58
Nocturnal Sweeping Customization
Decorative Banner #57
Enkephalin Box x2
Extraction Ticket
Nominable Egoshard Crate x5
Egoshard Crate x5
Identity Training Ticket IV x1
Identity Training Ticket III x1
Thread x5