Pneuma and Ousia Explained (Arkhe System)

Pneuma and Ousia are forms of opposing energy that flows in every life form from Fontaine in Genshin Impact 4.0. See how to trigger the Annihilation Reaction, the Arkhe System, list of characters that use Pneuma and Ousia, and all the known info about these here!

What are Pneuma and Ousia?

Opposing Forms of Energy in Fontaine

Pneuma and Ousia are forms of opposing energy in Fontaine that are separate from the Seven elements present in Teyvat. Playable Fontaine characters like Lyney and Lynette as well as the Hydro Traveler can access Pneuma and Ousia through the Arkhe System, a system exclusive to them!

Pneuma vs Ousia

There is no superior or inferior energy between Pneuma and Ousia - they just differ on which characters have a specific Pneuma or Ousia energy or which enemy uses a Pneuma or Ousia power supply.

There are a few ways to identify if your character is Pneuma or Ousia-aligned:

Difference in Vision Badge Style

Ousia	Pneuma
Rounded badge tips	Pointed badge tips

Characters with a Ousia-aligned vision have rounded top & bottom tips on their badges, while an Pneuma-aligned characters have pointed badge tips.

Difference in Attack Effect Colors

Pneuma	Ousia
Yellowish, gold energy	Dark, purple energy

Both energies can be differentiated by their colors when characters do certain attacks: Pneuma has a yellowish-gold color while Ousia has a dark, purplish color.

Can be Used by Characters Thru The Arkhe System

Some characters can manipulate Pneuma or Ousia in the form of Arkhe, which is a separate mechanic from their Vision. Only Fontaine characters have innate Arkhe attributes.

Arkhe Follows an Attack

The Hydro Traveler uses their Hydro Elemental Skill then followed up by a Pneuma-aligned Spiritbreath Thorn.

The Arkhe mechanic usually follows an attack using either the Elemental Skill or Charged Attack (Bow) of a character (so far). Be careful as these can also miss with some characters.

Arkhe Needs to Recharge

Each character also needs to recharge their Arkhe before it can activate again. Their vision will usually glow with Pneuma or Ousia's color when it is ready to use!

Pneuma Blocks Can Also Be Used

If players do not have characters that have Arkhe, most overworld puzzles provide Pneuma or Ousia Blocks that they can use to activate Pneumosia relays or overload opposite-aligned enemies.

Pneumosia Blocks in Fontaine

Results in Annihilation Reaction

When Pneuma and Ousia meet, a collision between the two opposing energies causes a reaction called Annihilation is formed.

Annihilation reactions create a form of energy that residents from Fontaine use to power up the whole Nation, and can also be against enemies who use Pneumosia energy!

Pneuma and Ousia Character List

As mentioned, only Fontaine characters and the Hydro Traveler have innate access to Pneuma and Ousia energies via the Arkhe system. Here are the known Fontaine Character Arkhe Types:

Pneuma Characters

Pneuma Characters
Lyney	Charlotte	Traveler (Hydro)
Freminet	Furina	Neuvillette

Ousia Characters

Ousia Characters
Lynette	Navia	Wriothesley
Sigewinne	Furina	Clorinde

You can tell a character's Arkhe type as early as their teasers, where you can sometimes spot the vision shape in their art, or when they appear during quests!

Note: Furina is the only character so far who can use both Arkhe.

Annihilation Reaction Details

How to Trigger an Annihilation Reaction?

1. Know the alignment of the unit you want to trigger the reaction with. Ousia is an energy with a dark, purplish color, while Pneuma has a yellowish-gold color to it.
2. Hit the enemies or the the mechanism with their opposing alignment. This means you must hit a Pneuma-aligned unit with Ousia, and an Ousia-aligned unit with Pneuma, to trigger the Annihilation Reaction!

Reacts with Clockwork Mekas

Pneuma and Ousia can be utilized by Meka life forms from Fontaine, primarily by machine beings called Clockwork Mekas. These Clockwork Meka beings can be found all over Fontaine, but only those who are inside the city walls are completely non-violent!

Disable Meka Enemies

When used against Meka enemies in Fontaine, the Annihilation reaction overloads their power supplies and stuns them for a short while. This allows Travelers to attack freely for a brief time.

Do note though that it takes a while for a Meka to recharge their power supplies, so further annihilation reactions won't happen if they are not charged.

Clockwork Meka Enemy Guide

Counters Some Boss' Unique Mechanics

Some more powerful boss enemies like Coppelia & Coppelius in Icewind Suite can have their unique mechanics broken by Annihilation reactions! Keep this in mind especially when the game adds these bosses to certain floors in the Spiral Abyss.

Interact with Mechanisms in Fontaine

Pneumosia Energy powers up a plethora of mechanisms that can only be found in Fontaine! From powering up locked storages and aircraft vehicles to relays all over Fontaine - it's a highly versatile form of energy!

Using annihilation reactions aid the Traveler in solving puzzles related to these so take note!

Fixing Pneumosia Relays

Reactions from clashing Pneumosia energies also fix Pneumosia relays which are central to some puzzles in Fontaine. Using the opposite energy reverts the relay back to its Balanced state, rendering it stable and activated.

Pneumousia Relay Guide

Deactivating Pneumousia Amplifiers

Pneumosia Amplifiers are troublesome devices that provides buffs to enemies. These are usually found in enemy camps all over Fontaine. Disable these devices using the opposite energy to disable their effects.

Activate Aircraft Puzzles

Annihilation reactions are used to power up The Miraculous Antoine Roger Aircraft, a new traveling vehicle when exploring Fontaine. This aircraft follows a set path and provides you with a treasure at the end of its journey. Be careful though as anomalies can happen mid-flight!

Fontaine Aircrafts Guide

Opens Huge Storage Vaults

Pneumosia energies are also used to store items and treasures all over Fontaine. Use the opposite energy to break them open!

Pneumousia Storage Box Guide

Pneuma and Ousia Release Date

Released in Version 4.0

Genshin Impact Version 4.0
Release Date	August 16, 2023

The Pneuma and Ousia mechanic debuted with Genshin Impact's 4.0 Update which introduced the Hydro region of Fontaine!

Version 4.0 Banners and Release Date

Genshin Impact Related Guides

Fontaine Map Guide

Fontaine Area Map Guides

Related Fontaine Map Guides
Liffey Region	Fontaine Research Institute
Fortress of Meropide	Merusea Village
Narzissenkreuz Ordo	Erinnyes
Morte Region	Tower of Gestalt
Nostoi Region	Sea of Bygone Eras

Fontaine Exploration Guides

Fontaine Exploration Guides
Diving Mechanic Guide	Underwater Area Guide
Fontaine Commission	Fontaine Reputation
Fontaine Craftable Weapons	Pneuma and Ousia
Local Legends	Xenochromatic Creatures
Ancient Symphony

Significant Fontaine Location Guides

Fontaine Location Guides
Hydroculus	Fountain of Lucine	Shrine of Depths	Enigmatic Page
Teleport Waypoints	Treasure Chests	Remarkable Chests	Secret Treasure Map

Fontaine Item Guides

Fontaine Local Specialties
Rainbow Rose	Lumidouce Bell	Romaritime Flower	Beryl Conch
Subdetection Unit	Lumitoile	Lakelight Lily	Spring of the First Dewdrop
Other Items Found in Fontaine
Tidalga	Marcotte	Pluie Lotus	Bulle Fruit
Condessence Crystal	Ancient Key	Drained Conch Cup	Mysterious Core
Hydro Sigil	Strange Part	Key to Some Place	Credit Coupons
Energy Concentrating Component	Mysterious Ore	Arkhium Ore	Arkhium Lumenite
Spur Gears	Welfare Meal	Handwheel	Punched Tapes
Foggy Forest Branch	Simple Vault Key	Autumn's Map	Rocky's Map
Liam's Map	Rouge's Map	Barrow Map	Parker's Hopes Map
Athos Map	Freeman Map

Fontaine Domain Guides

Fontaine Domains Guides
Denoument of Sin	Echoes of the Deep Tides
Pale Forgotten Glory	Waterfall Wen
Faded Theater

All Fontaine Domains and Locations

Fontaine Quest Guides

Ancient Colors Quest Chain
A Brush of Seafoam and Crimson	A Gradient of Dreams and Ochre
Blue Longing of Heart and Moon
Ann of the Narzissenkreuz Quest Chain
The Narzissenkreuz Adventure	Kingdom Through the Looking-Glass
“If She No Longer Dreams of You...”
Unfinished Comedy Quest Chain
Game of the Rich	An Eye for An Eye
Hereafter...	Scenes From Life in Meropide
In the Wake of Narcissus Quest Chain
Search in the Algae Sea	Muse's Mother
Meteoric Lance	Cupid's Lover
Thalia and Melpomene	Savior's Wake
Waking From the Great Dream	Rowboat's Wake
The Wild Fairy of Erinnyes Quest Chain
Foggy Forest Path	Wilting Weeping Willow
Furious Mouth of the Spring	Within the Depths of Erinnyes
Questioning Melusine and Answering Machine Chain
Vagrants and Scamps	The Red and the Black
Questions and Answers
Canticles of Harmony Quest Chain
The Shadow Over Petrichor	Underwater Nocturne
The Last Day of Remuria	Gradus ad Capitolium
Fortune Plango Vulnera	For Yesterday and Tomorrow
Erinnyes Region World Quests
Impromptu Poem of the Crimson Dawn	Free Verse
Morte Region World Quests
Wish-Fulfilling Treasure Hunt
Liffey Region World Quests
In Search of Lost Time	Our Purpose is in Another Canal
Both Brains and Brawn
Fontaine Research Institute Region
Fontaine Research Institute Chronicles	Road to the Singularity
A Letter	Treacherous Light of the Depths
Villains	An Expected Plan
An Expected Lie
Belleau Region World Quests
Still Mouthwatering!	Truly Mouthwatering!
Beryl Region World Quests
Book of Esoteric Revelations	Echoes of the Ancient World
Fishing Game	Good Stuff, but Terrible Taste
The Lone Phantom Sail	The Three Primary Colors of the Solar Corona
Were It So Easy	Strange Stone Chronicle
This Isn’t Pumpkin Soup…	Pursuit
Through the Looking Glass
Court of Fontaine Region World Quests
Another Horizon of Adventure	A Certain Notice
A Certain Trifle	A Certain Stamp
A Fontanian Message	Ann's Story: Prologue
Aqueous Tidemarks	Danger Lurks Everywhere in Fontaine
In Expert Company Part 1	In Expert Company Part 2
Self-Automatic Foraging	Seymour's Story: Prologue
Steambird Interview	The Final Question
The Fountain Flows Again	Unfinished Story
Upon a Flowery Field of Grass	Initial Facts
Happy Birthday	Where His Life Lies

Fontaine World Quests

4.6 Fontaine Puzzles and Features

4.6 Fontaine Features
Washer Octopus	Lost Grimoires and Mysterious Bookshelves
Wonderchime Flowers and Allochromatic Anemones	Summon Currents with Scylla
Music Score Locations	Auric Anglerfish
Break the Chains that Bind Scylla	Portus Anticus Luxurious Chest
The Flying Outlander Achievement Guide	Juliano's Hidden Chests
How to Pet Osse

4.2 Fontaine Puzzles and Features

4.2 Fontaine Features
Humongous Hat Jellyfish	Potential Energy Orbs
Operable Mechanisms	Reveal the Altar's Secrets
Pahsiv Shop	Decode This Level's Puzzle
Mary-Ann Brainstorming Answers	Salvage the Lost Items
Looking Glass Locations	Permingeat's Questions and Answers
Contaminated Bacterial Mats	How to Solve Dew Bubbles and Branches
How to Operate Dangerous Autocannons	Harmonious Reed Pipes
Floating Crystal Flowers and Platforms

4.1 Fontaine Puzzles and Features

4.1 Fontaine Features
Searchlight's Detection Range	Gear Drain Valves
Recover the Condensing Components	Central Laboratory Ruins Seelie Puzzle
How to Destroy the Thorny Cyst	How to Go to the Abandoned Production Zone
How to Solve the Forging Press Puzzle	How to Unlock Bravais' Secret Study
Strange Eels	Allogravity-Condensed Water Bodies
Red Meanies	Stabilizer
Drive Valve to Supply Warehouse 1	Flying Energy Thief
Experimental Focusing Mirror Puzzle	Cipher Letters
Energy Transfer Terminals	Fixed Storage and Energy Transfer Device
How to Retrieve All 4 Replica Anchors	How to Start the Optical Device
Retrieve the Anchor at the Institute Dormitories	Retrieve the Anchor at the Institute of Clockwork Applications
Remains of the Day Secret Achievement and Chest	Water Barrier Seelie
Rag and Bone Shop

4.0 Fontaine Puzzles and Features

4.0 Fontaine Features
Fontaine Aquabus Guide	Court of Fontaine Waypoints Unlock Guide
Heart Plant Co-Op Hidden Chest	Sonar Resonance Points
Underwater Currents	High-Pressure Water Vents
Recovery Orb	Fontaine Echoing Conch
Fantastical Floating Ball	Pneumosia Blocks
Miraculous Hydrograna	Beastly Rifts
Bullet Barnacles	Fontaine Aircrafts Guide
The Prism in Elynas	Water Volume Detection Crystal
Pneumousia Relay Guide	Pneumousia Storage Box
Sunken Objects	Scenic Attractions
Adjust the Prism	Berrypuff Hidden Quest
Locked Underwater Dome	Break the Treasure Seal
Break the Bubble Formations

Fontaine Enemies

Fontaine Boss Guides
Emperor of Fire and Iron	Icewind Suite	Millennial Pearl Seahorse
Experimental Field Generator	Hydro Tulpa	Statue of Marble and Brass
All-Devouring Narwhal	The Knave
Fontaine Enemy Guides
Fontemer Aberrants	Tainted Hydro Phantasm	Breacher Primus
Clockwork Meka	Fatui Operatives	Praetorian Golem
Local Legends Guides
Iron Viscount	Fairy Knight Twins	Ocean Circuit Judge
Vivianne of the Lake	Fading Veteran	Swords of the Gorge
Ninianne of the Lake	Dobharcu, Lord of the Hidden	Automated Supercomputing Field Generator
Luachra the Brilliant	Yseut	Liam
Rocky Avildsen	Mageblade Corrouge	Chassanion
Deianeira of Snezhevna	Cineas

All Interactive Map Guides

All Interactive Map Guides