Hollow Zero Lost Void Guide for Zenless Zone Zero

Hollow Zero Lost Void Guide for Zenless Zone Zero

In Hollow Zero: Shadows Lost, players can explore the "Lost Void", complete commissions and bounties, work on their Investigation License, and earn exclusive rewards! Check out the guide to learn more about this game mode.

Last updated on Jun 06, 2025 at 04:00 by Piyo
1.

Lost Void Shadows Lost in Zenless Zone Zero

Hollow Zero is the most expansive and influential Hollow in New Eridu. You, as an official member of the Independent Investigation Team, will need to support the investigation and suppression operations within Hollow Zero.

In Version 1.4, Zenless Zone Zero introduced a new expansion of Hollow Zero gameplay called Shadows Lost. Here, players can explore the "Lost Void", complete commissions and bounties, work on their Investigation License, and earn exclusive rewards! These rewards include BrawlerbooBrawlerboo, an exclusive Avatar and Namecard, Victoria Housekeeping Coupons, Polychromes, and more.

To view other Hollow Zero game modes, consult their respective guides below.

2.

How to Unlock the Lost Void and its Features

Depths Investigation: Lost Void

After players have unlocked Hollow Zero, which includes completing the Agent Story Mole in the Hole (I), the Lost Void and its Battlefront Purge Investigations will be immediately available, along with the game mode Withered Domain.

To unlock Special Operation Investigations in the Lost Void, players will need to complete certain Hollow Zero commissions. Please see the Special Operations section for more information.

To unlock Perpetrator Battle challenges, players will need to have completed a Battlefront Purge investigation at least once. This provides a basic understanding of the Lost Void's key features, such as Trial Agents and different types of Gears.

To unlock Shadow Operation explorations, players will need to have completed a Battlefront Purge investigation at Difficulty V. This mode is another alternative to Battlefront Purge for clearing the weekly Bounty Commissions.

To unlock Task Force Investigations, players will need to have reached Inter-Knot Level 42 and have cleared Battlefront Purge: Difficulty IV at least once in Lost Void.

3.

Lost Void Key Features

Lost Void Main Menu

In the Lost Void, the Hollow Zero Investigations are categorized under Special Operations, Battlefront Purge, Perpetrator Battle, and Shadow Operations. There are other features included, such as:

  • Investigation License and Weekly Bounties
  • Combat Potential Upgrade Nodes
  • Exploration Collection
4.

Key Features of Hollow Zero Lost Void

Special Operation Battlefront Purge Task Force Investigation Perpetrator Battle Shadow Operation
Power Adaptation and Trial Agents Potential Catalyst and Gear Difficulty and Ether Activity Investigation Strategy Seasonal Buffs
Key Comparisons Weekly Reset and Trial Agents Tactical Prism Programs and Prime Zero
4.1.

Power Adaptation

Power Adaptation

When players are setting up their Agents and Squad for the Investigation, they may opt to enable the Power Adaptation feature. This feature syncs the following Agent stats based on the Investigation Difficulty Level:

  • Level
  • W-Engine Level (Uses your Currently Equipped W-Engine or Auto-Recommended W-Engine)
  • Skill Levels and Core Skill Enhancements
  • Drive Disc Levels (Uses your Currently Equipped Discs or Auto-Recommended Disc Sets)

At Difficulties V and higher, you may only access the Power Adaptation feature for your current roster of Agents.

4.2.

Additional Notes and Exceptions

This feature does not affect an Agent's Mindscape Cinemas. In addition, the feature will only replace the relevant stat or equipment if the player's own Agent build is not up to par with the Investigation Difficulty recommendations.

For example, if your own Agent has the wrong W-Engine equipped, the feature will provide a different W-Engine instead (up to A-Rank). If your Agent does not have any Equipment equipped, the feature will provide a "Fairy" recommended set of Equipment instead.

4.3.

Trial Agents

Trial Agents

Every season, Battlefront Purge will feature Seasonal buffs that may prove useful for certain Agents. These Agents have a "Potential Catalyst," which enables them to use Exclusive Gears in Lost Void. They can be permanently trialed in the Game Mode Battlefront Purge, even if they are not currently featured on the Exclusive Channel.

Trial Agents are only available at Difficulties IV and below. At Difficulties V and higher, you may only use your personal roster of Agents.

If you play on a lower Difficulty than recommended, Trial Agents, unlike your own Agents, will sync down to the appropriate stats. They are always subject to the Power Adaptation feature. As a result, they may perform worse than your own Agents depending on your account's investment.

4.4.

Potential Catalyst and Exclusive Gear

Potential Catalyst in Agent Selection

When selecting Agents for the Investigation Squad, certain Agents will be able to use the Potential Catalyst feature. When investigating, if the Agent has a Potential Catalyst, they may obtain Exclusive Gear that can upgrade or change the Agent's skills.

Exclusive Gear

Note: Only one Agent per Investigation may have a Potential Catalyst enabled. If your squad has multiple Agents with Potential Catalysts, the game will force you to get Exclusive Gear for only one Agent. If this Agent dies in combat, you cannot receive Exclusive Gear for other Agents. If you choose to not use any Exclusive Gear, the game will provide you with only General Gears instead.

4.5.

Other Gear Types and Levels

General Gear

While players may receive Gear for Agents with Potential Catalysts, they may also receive Gear of other types too. These other Gears, known as General Gears, work the same way as most Resonia in Hollow Zero: they provide a manual Bangboo skill, as well as various supportive effects in combat.

Players can unlock Gear by using Mottled Ether Particles, which you can obtain by clearing Battlefront Purge runs.

These Gear Effects are mostly beneficial, though powerful bonuses may come with harmful side-effects. For a better understanding of General Gears, see the in-game Exploration Collection's Gear Database. For any General Gears you have yet to unlock, they can be reviewed by speaking with Ray at the start of Battlefront Purge Floor 1.

General Gears level up whenever you obtain multiple Resonia of the Same Type as the Gear, or if you purchase a Suction Welding Torch - Solvent Launcher Resonium from the Bangboo Store. The Resonia fusions will provide one Gear Level at a time, whereas the Suction Welding Torch - Solvent Launcher will maximize one General Gear's level.

Gear Level Example

Except for the initial General Gear given by Ray, the type of Gear you can receive while exploring is random; it is not directly correlated to the chosen Squad or Resonium kit for the Investigation. For example:

  • If your Resonium Kit is only of the Dexterity type and you receive a [Dexterity] Gear, the Gear will level up according to how many Dexterity Resonia you have. If you have 4 Dexterity Resonia, the Dexterity Gear would be Level 2.
  • If your Resonium Kit is only of the Dexterity type and you receive an [Ultimate] Gear, the Gear will not level up. If you do not receive anything related to the General Gear, whether it be Ultimate Resonia or the Suction Welding Torch - Solvent Launcher Resonium, it will remain at Level 1.

During a run, you can check your current Gear(s) and Resonium by accessing the side menu's Artifacts tab.

4.6.

Difficulty and Ether Activity

To participate in Battlefront Purge, players are required to select a Difficulty level for the Investigation. There are currently 6 Difficulty Levels to choose from, with the first 4 being available by default.

Battlefront Purge at Difficulty VI

To unlock Difficulty V, players will need to complete at least 1 Investigation at Difficulty IV (Recommended Agent Level of 50).

To unlock Difficulty VI, players will need to complete at least 1 Investigation at Difficulty V (Recommended Agent Level of 60).

To unlock Ether Activity challenges, players will need to complete 1 Investigation at that Difficulty. By increasing the Ether Activity Intensity, players can earn additional Shadow Crystal Data. This is primarily useful if you want to work through the Investigation License levels faster.

There are some Exploration Missions only available to complete at higher Difficulties.

4.7.

Shadow Crystal Data

By completing Investigations in the Battlefront Purge, players can receive a set amount of Shadow Crystal Data, which is used to contribute towards the Weekly Bounty and Investigation License progress.

Difficulty Shadow Crystal Data Amount
Difficulty I 1,250
Difficulty II 1,500
Difficulty III 3,000
Difficulty IV 3,500
Difficulty V and VI 4,000

Every week, for the player's First Clear, they will receive double of the Shadow Crystal Data for the run. For example, clearing Difficulty V as your First Run will net you 4,000+4,000 Shadow Crystal Data, for 8,000 Total. Any further runs, up to 45 total runs weekly, will continue to grant Shadow Crystal Data and other Regular Rewards.

If you have unlocked Task Force Investigation, the double reward mechanism mentioned above will be moved to that game mode instead. You will unlock Task Force Investigation upon clearing Battlefront Purge at Difficulty IV for the first time.

4.8.

Special Notes and Exceptions

Players are not required to complete lower Difficulties to receive the First-Clear Rewards. Any clear of a higher Difficulty will reward the cumulative amount, saving you from having to run the lower Difficulties.

In addition, if your account's Inter-Knot Level is too high compared to the Investigation Stage's level, you will not receive any Shadow Crystal Data for completing the Investigation. You can still receive the other Regular Rewards, up to the weekly limit of 45 runs.

4.9.

Investigation Strategy

Investigation Strategies

Before players can begin their run of Battlefront Purge, they need to select an Investigation Strategy, which provides beneficial effects based on certain areas you may encounter during the run. However, outside of combat-based Strategies, you may not encounter specific areas as they are randomized per run.

As a result, to make the most effective use out of your Investigation Strategy, players are recommended to check the Map before selecting an area and allocated path.

Complex Area in Battlefront Purge

For some nodes known as Complex Areas, they can feature multiple area types. In Complex Areas, your Investigation Strategy will apply to the relevant part of the map. For example, if you have Looting Strategy and the Complex Area features "Encounter" as the 2nd part of the Area, the Strategy Effect only works in the 2nd half of the Area, not the 1st.

At higher Difficulties, players will have more Investigation Strategies to choose from; as the Map becomes more complex, it provides additional opportunities to benefit from the chosen Investigation Strategy.

Explorer's Badge

At Difficulties V and higher, players can unlock a feature called the Explorer's Badge. Every Investigation Strategy has its own Explorer's Badge Level, which increases by every Rank 3 General Gear you collect in a run.

4.10.

Seasonal Buffs

Seasonal Buffs

When participating in the Battlefront Purge, players are required to select a Seasonal Buff of the options available. These buffs are beneficial in combat, as they increase the Squad's damage potential, on top of the Gears, Resonium Kits, and Investigation Strategy.

As these Buffs rotate every season, players can take advantage of them through their own Agents or the Trial Agents provided. For example, if the season specializes in Ice combat, players can trial the Ice Agents that are available. There are also more general Seasonal Buffs available, such as for Stun specialties instead of a DMG Type. As such, players should find at least 1 Seasonal Buff useful for the Investigation.

4.11.

Special Operations

In Special Operations, players can enjoy the Hollow Zero story commissions. These commissions provide additional lore for Hollow Zero, along with completion rewards. After players have unlocked Hollow Zero, they can complete the following Special Operation-related commissions:

Commission Name NPC Name Location Special Operation
Qualification Assessment Ray Scott Outpost: Inside the Tent Qualification Assessment
Tracking Down Clues Charlie Sixth Street: In front of Random Play Ray, Vanished
Dancing on Strings Ray Scott Outpost: Inside the Tent Reinvestigate the Lost Void
Phantom Path Yixuan Scott Outpost: Beside the Telescope Zero File: Miasma I

If players are having trouble finding the NPCs, they should select to Track the Hollow Zero commission so the game will prioritize its completion. Players can track commissions through the Inter-Knot Schedule menu.

Players can only use the Trial Mode while completing the missions in Special Operations. As such, your Agents are pre-determined and cannot be changed. The only exception to this is Qualification Assessment.

4.12.

Perpetrator Battles

Perpetrator Battle Menu

In Perpetrator Battle, players can complete challenges using a solo Trial Agent for additional rewards. These challenges have two levels of difficulty: Low Activity and High Activity.

Evelyn's Perpetrator Battle

As the Activity increases, players will need to fulfill requirements that are more difficult to complete, in addition to encountering tougher enemies. The High Activity area is only accessible after the player completes the Low Activity area for the specific Agent. Players can review the Key Enemy Info or their previous Combat Records for additional assistance with completing the challenges.

4.13.

How to Complete the Perpetrator Battles

Perpetrator Battle Squad Example

For each Perpetrator Battle challenge, players are only allowed to use the specified Trial Agent in the squad, along with a Bangboo of choice. If players do not have a fitting Bangboo, they can use a Trial Bangboo instead. The squad will also receive a predetermined supply of Agent-Exclusive Gears, along with general or Type-based Gears and Resonia.

Perpetrator Battle Current Supply

As the Trial Agent will not have additional support from other Agents, they will receive Tactical Enhancements, which can increase their combat potential. The Tactical Enhancement effects can be reviewed from the Activity section of the Challenge window.

Perpetrator Battle Agent Selection

If the player already owns the Trial Agent, they can opt to use their personal Agent instead.

For more information on what Trial Agents or Gears are, please see the relevant sections under Battlefront Purge.

4.14.

Time Limit and Exclusive Rewards

While the game mode is permanently available in the Lost Void and has its own First-Clear bonuses and Challenge rewards, Perpetrator Battle also features event-exclusive rewards for completing the challenges within a time limit of 14 days.

At the start of the event period, players will only be able to complete the challenges for one new Agent initially. Each subsequent Agent takes 24 hours to unlock from the previous one. As such, players can only play all of the challenges and receive the event-exclusive rewards after approximately 3 event days have passed.

While waiting for new Agent challenges to unlock, players can try out the Perpetrator Battles from previous seasons instead.

If players do not complete the event before the time limit expires, the exclusive rewards will no longer be available. This leaves only the First-Clear bonuses and base Challenge rewards for players to receive.

4.15.

Shadow Operations

Shadow Operations Menu

A Shadow Operation is an alternative way to collect weekly Shadow Crystal Data, helping you complete Bounty Commissions and level your Investigation License.

Nightmare Ordeal Stage

The primary feature of Shadow Operation is that each stage has a unique environment: you may receive initial supplies for free, or have some features disabled to pose as a challenge.

There are currently 8 Shadow Operations, where each one unlocks whenever you complete the most recent stage.

You can only receive rewards when clearing a Shadow Operations stage for the first time. The weekly Shadow Crystal Data can only be obtained if you have not completed the Bounty Commissions for the week yet. Each stage awards 4,000 Shadow Crystal Data for your first time clear, and 4,000 for the first weekly completion in a Bounty Commission cycle.

This game mode also disables any Combat Potential bonuses you may have. You also cannot review an exclusive Exploration Collection, nor complete any Lost Void achievements when playing through the Shadow Operations.

4.16.

Task Force Investigation

Task Force Investigation Menu

Introduced in Version 2.0, Task Force Investigations are a new game mode in Hollow Zero: Lost Void. Here, players can visit the Hollows in a similar fashion to Battlefront Purge, but with a few key differences.

Task Force Investigation can only be unlocked after players have successfully completed their first Battlefront Purge run at Difficulty IV. As such, if there are any clarifications needed on the general gameplay, consult the Battlefront Purge section.

Task Force Investigation shares some general gameplay with Battlefront Purge: your squad goes through randomized maps, collects Resonia and level up General Gears, has Investigation Strategies and Ether Activities, and is a valuable source of Shadow Crystals and Shadow Crystal Data.

So what exactly is different? Well, Task Force Investigations...

  • Does not feature Seasonal Buffs
  • Removes the Double Shadow Crystal Data Weekly Reward from Battlefront Purge upon Unlock
  • Provides a Weekly Bonus if you clear with a Featured Trial Agent
  • Exclusive Gears have been "upgraded" to Tactical Prism Programs
  • Bangboo Stores feature a unique item per run called Prime Zero
  • Task Force Missions are exclusive to Trial Agents in your squad

For more information on each difference, consult the various categories under this section.

4.17.

Weekly Bounty Commission Reset

Every week, Task Force Investigations will introduce a new roster of Agents for players to use while exploring. Completing the Investigation with the Roster Agents will provide you with additional rewards.

After clearing your first Task Force Investigation for the week, players can obtain double the Shadow Crystal Data, allowing you to quickly finish your Bounty Commissions. This is significantly faster than clearing a Battlefront Purge at Difficulties lower than V.

4.18.

Trial Agents and Potential Divergence

Task Force Investigation Trial Agent Selection

The Trial Agent roster does not only include the ones featured for additional rewards; it includes every Agent who has Tactical Prism Programs in Task Force Investigations. This allows players to complete their Task Force Missions, which are unique to each applicable Agent, at any time.

Task Force Investigation Potential Divergence

Players can view what Tactical Prism Programs are available for an applicable Agent using the Potential Divergence button at the top of the Agent Selection screen. If the Agent cannot use Tactical Prism Programs, they will not have the option available.

Compared to Battlefront Purge, Trial Agents are not subject to the Power Adaptation feature. This is because Task Force Investigations only has one Difficulty mode available. Only your own Agents can be subject to Power Adaptation when selected. Additionally, you cannot use the Trial version of the Agent if you already own them.

4.19.

Tactical Prism Programs

Tactical Prism Programs

Tactical Prism Programs are the updated version of Exclusive Gears for Agents. Tactical Prism Programs have two distinct features to them: Other Squad Agents can also equip their own Tactical Prism Programs within the same run, and you can choose which combat abilities to enhance as you progress through the run.

Tactical Prism Program Branches

Just like any Gear Type, Tactical Prism Programs can level up. Unique to Tactical Prism Programs are Branches: Tactical Prism Programs can "branch out" into different upgrade effects, known as Path Alpha and Path Beta. So your Tactical Prism Programs may not upgrade the same way every run.

Tactical Prism Programs do not replace General Gears in Task Force Investigations, nor are they featured in Battlefront Purge runs.

4.20.

Prime Zero Items

Prime Zero in the Bangboo Store

You can obtain Tactical Prism Programs through any Combat - Gear or similar reward map nodes, including the Bangboo Store. At the Bangboo Store, only one Prism Program can be obtained during the run; this is called the Prime Zero item.

After you have purchased the Prime Zero item, you can no longer obtain additional Tactical Prism Programs through the Bangboo Store for that run.

5.

Investigation License

Lost Void Investigation License

As players complete the various Lost Void game modes, they can gather Shadow Crystal Data, which is used to progress their Investigation License. This Investigation License, independent of the one featured in the Withered Domain, provides the following rewards:

Exclusive to Lost Void:

  • BrawlerbooBrawlerboo and its Core Updates
  • Victoria Housekeeping Coupons (Use to Instantly Complete a Routine Cleanup)
  • At Level 15: "Puppeteer's Letter" Namecard
  • At Level 35: "Final Dose" Avatar
  • At Level 90: "Something Certain" Namecard
  • At Level 100: "Plundering the Core" Avatar

As well as common Hollow Zero rewards like:

  • Polychromes
  • Boopons
  • Bangboo Level Cap Materials
  • Inter-Knot Credits
  • Hi-Fi Master Copies
  • Tuning Calibrator
  • Hamster Cage Pass
  • Dennies

Note that the Shadow Crystal Data, which is used to level up your Lost Void License, is only available to collect up to 45 times per week. From the 46th run onwards, players will not be able to receive any rewards until the next reset.

Any Investigation Points received from the Withered Domain, the other Hollow Zero game mode, will not progress the Investigation License for the Lost Void.

As of Version 2.0, the maximum level the Investigation License can reach is Level 160.

6.

Weekly Bounty Commissions

Lost Void Weekly Bounty Commissions

Whenever players clear the various game modes in Lost Void, they will receive Shadow Crystal Data which contributes towards the Investigation License, as well as the Bounty Commissions. By completing all of the Bounty Commissions, players can receive the following rewards every week:

  • 160 Polychromes
  • 1,000 Z-Merits
  • Bangboo Level Cap Materials
  • 5 Boopons
  • 3 Victoria Housekeeping Coupons
  • 1 Master Tape

Players will receive the rewards when they obtain their first 2,000/4,000/6,000/8,000 Shadow Crystal Data for the week. After 8,000 Shadow Crystal Data, players will not receive any more Bounty Commission rewards for further runs, but they may continue leveling up their Investigation License up to 45 times a week. The Bounty Commissions reset every week.

7.

Combat Potential

Lost Void Combat Potential

As players complete more Investigation runs of Battlefront Purge in the Lost Void, they will also obtain Shadow Crystals, which can be used to unlock Nodes in the Combat Potential Menu.

Note: Shadow Crystals are for the Combat Potential Nodes, whereas Shadow Crystal Data is used for the Investigation License and Bounty Commissions.

By unlocking Combat Potential Nodes, players can enable certain beneficial effects during their runs. For example, some Nodes will directly affect combat, such as increasing the amount of Ether Dewdrops (to revive Agents) or increase the Dodge Counter DMG. Other nodes may affect certain Map Areas, such as increasing the Health Recovery and adding a Revive feature in "Rest and Recovery" Areas.

7.1.

Node Levels and Expertise Points

As players obtain more Shadow Crystals, they can upgrade their Nodes and its effects up to Level 3. Each Node requires a minimum of 100 Crystals to unlock, and a total of 500 Data to reach Level 3.

The total amount of Nodes currently available is 25, so players will need to obtain a maximum of 12,500 Shadow Crystals to complete their Combat Potential.

To further enhance a Node's effects, players also have 5 Expertise Points they can use. After a Node reaches Level 3, players can choose to Expertise Boost the Node, consuming 1 Point per Node. This increases the Node Level to 3+.

If players made a mistake with their Expertise Points, or wish to use them elsewhere, they can refund at no additional cost via the Cancel Expertise button. You cannot downgrade or refund Combat Potential Nodes otherwise.

8.

Exploration Collection

Lost Void Exploration Collection

After completing the Battlefront Purge, players may view the Exploration Collection menu for a list of all the Explorer Badge levels, Gear, Resonium, and Cards collected so far. If players reach certain collection progress points for each category, they can receive rewards such as Polychromes, Dennies, and Bangboo EXP Materials.

You can unlock the Unofficial Guide logs by completing the Unofficial Guide achievements in Battlefront Purge at Difficulty V or higher.

The Lost Void's Exploration Collection is a unique feature; the other Hollow Zero game mode, Withered Domain, has its own Exploration Collection that is filled out separately through Withered Domain's own game modes.

8.1.

Affinity Resonia in Lost Void

Lost Void Affinity Resonia

Players can obtain Affinity Resonia if they meet all of the following conditions:

  • Obtain a Trust Level of Close or higher with the Agent
  • The Agent dealt the killing blow in a Battlefront Purge map node: Combat - Crisis on the Road

Speak with the Agent in the subsequent Friendly Talk map node to obtain the Affinity Resonia.

Knock-Knock DMs

Players can increase an Agent's Trust Level by interacting with them in the neighbourhood overworld, or through the Daily DMs feature in Knock-Knock. The Lost Void Affinity Resonia are the same as the ones in Withered Domain.

8.2.

What is the Explorer Badge?

Explorer's Badge

Once players have reached Difficulty V in the Battlefront Purge, they may receive an Explorer's Badge if the General Gear obtained reaches at least Rank 3 during a run at Difficulty V or higher.

Each Investigation Strategy has its own Explorer's Badge Level: in order to obtain the specific Badge, you will need to complete the Battlefront Purge run while the Investigation Strategy is selected.

In addition, you also need to obtain various Rank 3 General Gears to level up the Explorer Badge for that Investigation Strategy. For example, obtaining two Rank 3 Gears in one run will provide 2 Explorer's Badge Levels for the Investigation Strategy.

9.

Lost Void Rewards

By completing content in the Lost Void, including the Weekly Bounty Commissions, players can receive the following rewards, on top of the Combat Potential upgrades:

Exclusive to the Lost Void:

  • BrawlerbooBrawlerboo and its Core Updates
  • Victoria Housekeeping Coupons (Use to Instantly Complete a Routine Cleanup)
  • "Puppeteer's Letter" Namecard
  • "Final Dose" Avatar
  • "Something Certain" Namecard
  • "Plundering the Core" Avatar

As well as common Hollow Zero rewards such as:

  • Z-Merits (Exchange at Outpost Logistics)
  • Polychromes
  • Master Tapes
  • Boopons
  • Bangboo Level Cap Materials
  • Inter-Knot Credits
  • Hi-Fi Master Copies
  • Tuning Calibrator
  • Hamster Cage Pass
  • Dennies
9.1.

Changelog

  • 06 Jun. 2025: Added Task Force Investigation section. Updated information for Version 2.0.
  • 04 Jun. 2025: Added links for other Hollow Zero game modes.
  • 02 Jun. 2025: Updated Section Wording for Version 1.7. Added Images and Shadow Operation section.
  • 17 Feb. 2025: Updated Section Wording and Added Perpetrator Battle Section.
  • 24 Dec. 2024: Page added.
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