Hollows

Hollow Zero

Hollow Zero is a codename for the oldest, most impactful, and most hazardous Hollow in all of New Eridu. It has been assigned the highest Danger level by the Hollow Investigative Association.

Trailer for Hollow Zero

All major Hollows discovered in New Eridu derive from Hollow Zero's Companion Hollows.

Hollow Zero is also responsible for most of the destruction of the old capital, Eridu.

It is vast in size, with many layers to explore. Ether activity inside Hollow Zero is volatile, and any activity here goes hand-in-hand with the threat of corruption.

Inside, a small number of stable areas exist, which provide goo entry points for additional exploration.

"Wise, we finally have a chance to explore Hollow Zero!"

"Remember to call a few Agents to get ready to come in as backup whenever needed, just in case."

"Don't worry, bro. I just gave Nicole and the gang a buzz. They'll be waiting at the entrance to the Hollow, ready to come in whenever."

"Good. Then let's head out!"

- Fairy Library: Hollow Zero

Investigation

New Eridu regularly schedules capable Agents to conduct research, investigate, track, and suppress Hollow Zero's development.

Source: HoYoVerse

Access

Hollow Zero becomes available once the player completes the mission, "Earlybird Ticket to Safety." Etheric Matter samples can be obtained while exploring Hollow Zero.

Squad

To explore Hollow Zero, players need to create a squad of three agents. One agent must be designated as the "Leader," who will first explore alone. The other two agents will be designed as "Backup," and can join the leader as backup slots open up.

When entering Stable Areas in the Hollows, you can make a Random Call to one Backup Agent to come in as reinforcements.

If you do not need an Agent's support, you can record the Agent's message to your REinforcement Beacon Bangboo Plug-In.

If you do need an Agent's help, use a Reinforcement Beacon to instantly call a Backup Agent to come in and help you.

Exploration

Hollow Zero is similar to a regular Hollow, where exploration is done by moving a Bangboo around a TV board.

Unlike regular Hollows, Hollow Zero is divided up into four different areas based on how deep into the Hollow you are:

Edge
Interior
Heartland
Core

Each has several floors for exploration. To complete a floor, you must defeat enemies at the end of the floor.

The exist on the final floor has a Final Threat. Defeat it to complete the exploration of the whole area.

On some special floors, your actions may create spatial anomalies, so be careful when planning your route.

Pressure and corruption

In Hollow Zero, every step you take, with the exception of special board tiles like Safety Zones, will generate 10 Pressure.

Once Pressure reaches 100, a random Corruption will appear and the current Pressure will be cleared.

Corruption can have adverse effects on both combat and exploration. Details can be checked in the Corruption tab.

Resonia

Hollow Zero contains some Hollow Investigative Association support supplies which include Resonia. Collect Resonia to give your team a combat buff or an exploration buff.

Resonia come in several types includes General, Critical, Energy, Dodge, and more.

Collect 4 or 8 Resonia of the same type to generate a bonus Advanced Resonium.

The Resonium Inventory can be opened to view all the Resonia you have collected as well as their effects.

Resources

Gear Coins can also be gathered while exploring Hollow Zero, and they can be used in Bangboo Shops to buy Resonia.

Rewards and resets

Every floor cleared while exploring Hollow Zero will yield Etheric Matter samples.

Even if you fail to defeat the final enemy, you will still get a certain ratio of Etheric Matter samples.

During the investigative period, you can claim investigation rewards based on the number of Etheric Matter samples collected.

Upgrade your Inter-Knot Level to increase the maximum number of Etheric Matter samples that can be collected within a given period, and unlock investigation rewards such as more Slots.