Flay – Barbarian Build for Diablo 4 (Season 9)

Build Introduction

Welcome to the comprehensive guide for the Flay Barbarian! A new generator build that emerged during Season 4 and has proven to be a powerful endgame and pit boss killer. If you like DoT-based playstyles and ramping up massive bleeds, this build is for you. The previous season added a ton of power to this, making it even better. So without further delay, let’s dive right in!

Strengths and Weaknesses

Build Requirements

Required Uniques

Rage of Harrogath

Fists of Fate

Ugly Bastard Helm

Hooves of the Mountain God

Shard of Verathiel

Ramaladni’s Magnum Opus

Required Aspects (Non-codex)

Aspect of the Moonrise

Aspect of Adaptability

Aspect of Earthquakes

Quick Navigation

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Skill Bar and Skill Tree Points

Recommended

Suggested Skill Bar

Flay Rupture Rallying Cry War Cry Challenging Shout Wrath of the Berserker

Follow the points allocated in the image above for the complete 71-point build. The additional 10 skills are completed using the Renown system.

Barbarian Class Mechanic – The Arsenal System

The Barbarian can wield four weapons simultaneously as well as choose a weapon expertise to use as their Technique, allowing them to gain that weapon’s bonus even if they’re wielding another weapon type. Finally, the Barbarian can assign its skills to use different weapon types shuffling between Two-Handed Bludgeoning Weapons, Two-Handed Slashing Weapons, and Dual-Wield Weapons.

For this Flay build, we will be using Two-Handed Axe as our weapon technique for its bonus to Vulnerable damage as this is still our strongest option. For both Flay and Rupture we’ll be assigning both skills to our Dual-Wield Weapons to benefit from Ramaladni’s Magnum Opus

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Gear, Stats, Gems, and Runes

The following sections will cover all systems that are critical if you want to improve the power of your character and move towards the highest difficulties in the endgame of Diablo 4.

Legendary Aspects

Below you will find all of the best-in-slot Aspects found on Legendary items that are important for this build. Remember that all Legendary powers can be added into your Codex of Power once you salvage or extract the item. You can still find some aspects through dungeons though they will always be at the minimum power level. To get the most out of this system, combine these Aspects with the right stats.

Slot	Gems	Legendary Aspect / Unique Item	Aspect / Unique Power
Helm	Grand Ruby	Ugly Bastard Helm	– Casting Wrath of the Berserker causes you to explode dealing [X] Fire damage. While Wrath of the Berserker is active your direct damage dealt is converted into Fire. You deal x[40-60%] increased Fire damage.
Chest	Grand Ruby	Rage of Harrogath	– Lucky Hit: Inflicting Bleeding on an enemy has up to a [20-60%] chance to reduce the cooldowns of your skills by 1 second
Gloves	N/A	Fists of Fate	– Your attacks randomly deal 1% to [200-300%] of their normal damage
Pants	Grand Ruby	Aspect of Bul-Kathos	– Leap creates an Earthquake that deals [X] physical damage over 4 seconds (We do NOT care about this line) While standing in Earthquakes and for 4 seconds afterwards, you gain [10-25%] increased Damage Reduction.
Boots	N/A	Hooves of the Mountain God	– When reaching Maximum Fury, your Fury will rapidly drain until you run out and all your Basic Skills now cleave and deal x[70-100%] increased damage.
Amulet	Scornful Light	Aspect of Adaptability	– When cast below 50% Maximum Resource, Basic Skills generate 3 of your Primary Resource once per cast. When cast at or above 50% maximum resource, Basic Skills deal x [20-80%] increased damage
Ring 1	Elemental Brand	Bold Chieftain’s Aspect	– Whenever you cast a Shout Skill its active cooldown is reduced by [10-30%] per nearby enemy up to a maximum of 50%
Ring 2	The Starflux	Aspect of Inner Calm	– Deal x[5-13%] increased damage. Triple this bonus after standing still for 3 seconds.
Two-Handed Bludgeoning Weapon	Igni and Tec Runes OR Grand Emerald	Aspect of the Moonrise	– Damaging an enemy with a Basic Skill grants you 4% attack speed for 10 seconds, stacking up to 5 times. Upon reaching maximum stacks, you enter a vampiric bloodrage, gaining x [40-60%] basic skill damage and 15% movement speed for 10 seconds
Two-Handed Slashing Weapon	Ahu and Qax OR Grand Emerald	Aspect of Earthquakes	– Ground Stomp create an Earthquake that deals [X] Physical damage over 4 seconds (We do NOT care about this line) While standing in Earthquakes and for 4 seconds afterwards, you deal x[25-60%] increased damage.
Dual Wield Weapon 1	Grand Emerald	Ramaladni’s Magnum Opus	– Skills using this weapon deal [0.2-0.5%] increased damage per point of Fury you have, but 10 Fury drains per second
Dual Wield Weapon 2	Grand Emerald	Shard of Verathiel	– Basic Skills deal x [50-150%] increased damage but additionally cost 25 Primary Resource

To see how this build compares to the other builds on our site, you can check out our build tier lists.

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Stat Priority and Tempering Affixes

Below are the affixes to prioritize on gear. Each line of affixes is listed in order of importance. Tempering Manuals and their recommended affixes are provided in the second column, and the bolded yellow affixes are the most important targets for Masterworking upgrades. Be sure to check our Tempering and Masterworking guides for more details about these topics.

Slot	Gems	Gear Affixes	Tempering Affixes
Helm	Grand Ruby	1. Cooldown Reduction 2. Strength 3. Maximum Life	1. Barrier Generation Natural Schemes 2. Challenging Shout Cooldown Reduction Barbarian Strategy
Chest	Grand Ruby	1. Strength 2. Armor 3. Maximum Life	1. Barrier Generation Natural Schemes 2. Challenging Shout Cooldown Reduction Barbarian Strategy
Gloves	N/A	1. Attack Speed 2. Strength 3. Lucky Hit Chance	1. Damage While Wrath of the Berserker is active Berserking Finesse 2. Barrier Generation Natural Schemes
Pants	Grand Ruby	1. Ranks to Flay 2. Strength 3. Needed Resistance	1. Barrier Generation Natural Schemes 2. Challenging Shout Cooldown Reduction Barbarian Strategy
Boots	N/A	1. Ranks to War Cry 2. Armor 3. Strength	1. Movement Speed Natural Motion 2. Crowd Control Duration Natural Schemes
Amulet	Grand Diamond	1. Ranks of Cut to the Bone 2. Strength% 3. Ranks to Counteroffensive	1. Wrath of the Berserker Cooldown Reduction Ultimate Efficiency — Barbarian 2. Damage While Wrath of the Berserker is active Berserking Finesse
Rings	Grand Diamond	1. Attack Speed 2. Strength 3. Resistance to All Elements (If needed) 4. Maximum Life	1. Wrath of the Berserker Cooldown Reduction Ultimate Efficiency — Barbarian 2. Damage While Wrath of the Berserker is active Berserking Finesse
Bludgeoning Weapon	Grand Emerald	1. Strength 2. Vulnerable Damage 3. Maximum Life	1. Flay Duration Furious Augments 2. Damage While Wrath of the Berserker is active Berserking Finesse
Slashing Weapon	Grand Emerald	1. Strength 2. Vulnerable Damage 3. Maximum Life	1. Flay Duration Furious Augments 2. Damage While Wrath of the Berserker is active Berserking Finesse
Dual-Wield Weapon 1	Grand Emerald	1. Strength 2. Maximum Life 3. Vulnerable Damage	1. Flay Duration Furious Augments 2. Damage While Wrath of the Berserker is active Berserking Finesse
Dual-Wield Weapon 2	Grand Emerald	1. Strength 2. Maximum Life 3. Vulnerable Damage	1. Flay Duration Furious Augments 2. Damage While Wrath of the Berserker is active Berserking Finesse

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Uniques and Mythic Uniques

Uniques received a large rework a few seasons ago. They can now roll much higher ranges and break all the traditional itemization rules for what stats can appear on which slots. Below, you will find the Uniques and Mythic Uniques useful to this build.

• Hooves of the Mountain God – The new unique boots in town! This item finally allows the Barbarian to live the Basic Skill dream. These are REQUIRED to run this setup due to their powerful damage multiplier to basic skills, and ability to let your basic skills hit multiple targets cleaving all around you.
• Rage of Harrogath – A powerful chest for Bleed based builds that was updated in patch 1.4 and maintains its potency in Season 5. Since we’re applying bleeds constantly through Flay we’ll be resetting our Shouts and defensive cooldowns all the time.
• Fists of Fate – What used to be a meme item or one recognized as not particularly powerful has received a large buff in Season 5. Now boasting up to a massive 51.8% Lucky Hit chance, this item can get us to trigger our various effects on nearly every cast of our skills. The damage bonus might look bad at first, seeing 1% but on average the item results in a 50% damage increase if you’re attacking fast enough and we aim to strike fast and hard with Flay.
• Shard of Verathiel – A new unique in season 5. This turns basic skills in powerhouses that cost a bit of resource. As Flay is a Basic Skill, the damage will be buffed by this new item significantly. Flay geneates 15 Fury per swing and costing 25 means the net Fury loss is only 10, we can mitigate this through paragon nodes, rolls on our gear, and our tempers meaning this cost is largely negligible but the damage increase is massive. A must have for any Basic Skill build.
• Ramaladni’s Magnum Opus – A tried and true staple of some Barbarian setups in the past makes a return for this basic skill build. By using dual-wield on Flay we’re able to benefit from this item’s huge bonus and add even more damage at the cost of some fury drain which is well worth it. This item is also why we like gearing for Max Fury as each point of fury adds more damage from this item’s effect.

Mythic Uniques

Mythic Uniques are extremely rare items that only drop from very end-game bosses such as Duriel and Andariel, as well as the Tormented versions of all bosses. Below, you will find a list of Mythic Uniques useful to this build. If a Mythic Unique isn’t listed, it isn’t useful to this setup.

• Ring of Starless Skies – A powerful unique that’s been the cornerstone of a few builds in the game’s lifespan. it retains its killer potency in the current game. If you’re lucky enough to acquire one, you drop the Bold Chieftain’s Aspect for it and it should provide you a nearly endless source of Fury from your Flay despite the Shard of Verathiel’s cost.

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Gems and Runewords

Listed below are the best gems to socket into your items for each slot type

Gems

Weapon Gems	Armor Gems	Jewelry Gems
Grand Amethyst for increased Damage Over Time	Grand Ruby for increased Strength	Horadric Jewels OR Grand Diamond for increased all resistances

For your jewelry, it may be necessary to change the Grand Diamond for another gem of a specific type such as Grand Sapphire to ensure all of your resistances are capped at 70% and your armor is at 1000. In Season 9, you’re able to acquire new special gems for your Amulet and Rings called Horadric Jewels. These will be the most powerful option if you have them. See our season 9 information below to find out which ones to use and what they offer!

Runes

Runewords return from Diablo 2 in Vessel of Hatred! You are limited to two Runewords across your gear, and it requires two sockets in the same item. So this limits creating Runewords by combining two Runes to either Helm, Chest, Pants, or Two-Handed Weapons. We generally recommend them in both of your Two-Handed Weapons for Barbarian. Let’s jump in.

Runes	Rune Effects
Igni	Gain 25 Offering: Stores Offering every 0.3 seconds. Cast a Non-Basic Skill to gain the stored offering
Tec	Requires 50 Offering, Cooldown 1 Second: Invoke the Barbarian’s Earthquake, dealing damage to enemies within
Ahu	Gain 15 Offering: Lucky Hit: Up to a 100% chance against Non-Healthy Enemies
Qax	Requires 400 Offering, Cooldown 1 Second: Casting a Skill other than a Basic Skill or Defensive spends all your Primary Resource to increase your damage by 100% for 1 second.

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Paragon Board

We recommend using the following Legendary nodes and Glyphs to truly take this build into the endgame. Note that each Glyph’s information and radius listed below is for the Level 100 version. As a note, Glyph’s reach their maximum radius and Legendary Bonuses at level 46. Let’s take a look!

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Horadric Spell (Season 9)

Season 9 brings a new complex mechanic that modifies your skills by attaching an ancient Horadric Catalyst to one of them, which you can then modify further with spells and infusions, causing some very potent combos. For this build, we recommend the following setup:

Type	Power	Description
Catalyst	Disintegrate (pair with Flay)	Form an Arcane Conductor that emits a persistent beam between itself and you, dealing a steady blitz of 18,130% damage over 8 seconds. Rank 10+: Enemies within the beam are Slowed by 50%
Infusion	Smoldering Ember	Your Catalyst now deals Fire and/or Burning damage. It destroys enemy structures and has a 10% chance to ignite the ground beneath enemies dealing 1,215% Burning damage over 5 seconds. While equipped, your Fire Damage Bonus is equal to that of your highest Damage Type Bonus. Rank 5+: Deactivates monster Chilling Winds effects for 5 seconds.
Arcana	Fractured Core	Your Catalyst deactivates monster Damage Resistance Aura effects for 5 seconds, but you take 15% more stacking damage for the same duration
Arcana	Siphoning Gizmo	Lucky Hit: Damage from your Catalyst has up to an 80% chance to consume Damage Over Time effects and deal 100% of their damage instantly
Arcana	Bloody Charm	Your Catalyst gains a specialized Execute effect for non-Boss enemies with 20% or less life. Bloody Charm creates the following effects for each Catalyst: Disintegrate – Non-Boss Enemies with 20% or less life are immediately Executed. This threshold is doubled for Non-Elite enemies.

Assign your Catalyst to Flay

Horadric Jewels

Additionally, Season 9 brings back new special gems for your Amulets and Rings called Horadric Jewels. We recommend the following gems for this build:

• Scornful Light – You deal x20% and take x10% more Elemental Damage
• The Starflux – Your Catalysts deal x100% more damage. However, you lose control over Horadric Spellcraft, causing your Catalysts to inherit infusions randomly
• Elemental Brand – Your Catalytic Skill deals 33% damage of your infusion’s element over 3 seconds. Lucky Hit: Dealing damage of your infusion’s element has up to a 33% chance to trigger its secondary effect.

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Mercenaries

As you play through the campaign in Vessel of Hatred, you will unlock various NPC Mercenaries who can join you on your quest to slay demons. Each Mercenary has their own small talent tree that will give them bonuses and skills to help you. Additionally, you can assign a Mercenary that you don’t take with you as a reinforcement to jump in when you activate certain skills. Let’s take a look at how we want to set this up for this build.

We hire Varyana, the Berserker Crone:

• Core Skill: Cleave
• Core Skill Passive: Hysteria
• Iconic Skill: Bloodthirst
• Iconic Skill Passive: Bloodlust

Our Reinforcement Mercenary will be Subo, The Drunken Archer:

• Opportunity Skill: War Cry
• Reinforcement Skill: Trip Mines

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Build Mechanics

Rotation and Playstyle

This is a fairly straightforward DoT-based playstyle. We want to be spamming Flay as often as we can. It has an innately high Lucky Hit chance, 50%! This will trigger our various sources of crowd control from our tempers. This will amplify the damage from the Aspect of Creeping Death. Once we’ve stacked Flay high enough, we can Rupture to rip it all out and cause huge damage. Let’s quickly go over how each skill is used:

• Flay our main attacking skill. We want to attack with this at all times.
• Rupture is used once you’ve got enough Bleed on strong enemies such as Bosses or Elites to kill them.
• Rallying Cry to generate some starting resources and get the build rolling
• War Cry for Berserking and give us a large damage increase.
• Challenging Shout for survival whenever you’re surrounded by large groups of enemies. Thanks to Tactical Challenging Shout it will also help you keep your resources high to trigger Hooves of the Mountain God
• Maintain as much uptime on Wrath of the Berserker as possible. This will provide us with resources yes, but most importantly the huge damage amplification of Ugly Bastard Helm which gives up to a 100% damage multiplier.

Runeword Synergy

Let’s take a moment to review our runes and how they interact with this build

• Igni will build up resources passively as you play and since it only triggers on Non-Basic skills, you trigger it whenever you press a Shout, Rupture, or Wrath.
• Tec spawns our Earthquakes for us through Igni whenever we shout or use cooldowns. Earthquakes aren’t the damage focus on this build, instead we stand in them to gain the damage multiplier from Aspect of Earthquakes and the damage reduction from Aspect of Bul-Kathos simultaneously.
• Ahu gives us 15 offering whenever we lucky hit enemies with less than 80% HP or “Non-healthy Enemies” which should be all of them since we’re bleeding them and we’re attacking very fast and furthermore, Flay has a very high lucky hit chance because it’s a Basic Skill. This should build up offering for us very quickly
• Qax eats all of our fury in one go to provide a massive damage amp for 1 second. Since this only triggers when we use Non-Basic Skills this build is better poised to wait until we stack a lot of bleed up and then casting Rupture will trigger this rune and deal a large amount of damage ideally killing our foe in one fell swoop. This will feel a bit odd on resources but thanks to Hooves of the Mountain God‘s Fury Per Second line, we should be back in the action in no time.

Which Elixirs Should You Use?

When in town you can visit the Alchemist to craft helpful elixirs which will provide a special effect and increase your experience gain. Crafting has been simplified as of Patch 1.4.0, and there are fewer specific flowers to harvest; instead, almost all herbs in the world drop as Bundled Herbs, allowing you to craft the elixirs you want. Some elixirs cannot be crafted and can only drop from things like Helltide or Nightmare Dungeons.

For this build, we recommend Elixir of Resourcefulness for the increased Fury so we can further increase the bonus from Ramaladni’s Magnum Opus and gain even more damage than we would from other Elixir options.

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Season 9 Updates

For a comprehensive look at what’s new in Season 9, please check out our Season Hub.

Here is a quick list of the changes this season that are relevant to this build:

• Flay damage over time increased from 48% to 110%
• Enhanced Flay Vulnerable proc chance increased from 15% to 50%
• Aspect of the Moonrise damage bonus reduced from 40-100% to 40-60% but ranks increased from 16 to 21
• Aspect of Adaptability changed to cause basic skills to generate 5 additional resource once per skill cast, basic skills now deal 0.4-0.6% increased damage per point of primary resource you have
• Ugly Bastard Helm damage bonus reduced from 80-100% to 40-60% and now requires Wrath of the Berserker to be active
• Wrath of the Berserker now lasts 10 seconds rather than 5 seconds with a 5 second extension caused by skill casts
• Hemorrhage changed, now applying bleed to a vulnerable target deals 45%x increased damage

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Obol Gambling

A final point on acquiring gear is using your Obols to target farm specific slots instead of randomly spending them on random drops. Similar to Kadala in Diablo 3, you can use Obol vendors in town to try and get what you’re missing. With the expansion when a level 60 Character spends Obols, all gear from that vendor will be 750 item power, the highest non-ancestral power allowing you to fill out gear with the affixes or Legendary Aspects you need while also having a small chance to grant Ancestral item power 800 gear.

Check out our Obol Gambling Tool Guide HERE.

ths we took on your boards that we didn’t take in our initial journey or any normal nodes for stats you might be lacking to gain bonuses for your various rare nodes. Congratulations on making it this far!

Changelog

• June 28th 2025: Build updated for new unique and Season 9
• April 25th 2025: Reformatted and updated for Season 8
• March 31st 2025: Skill tree recommendations updated
• January 19th 2025: Tooltips and Seasonal section updated for Season 7
• January 14th, 2025: Build updated for Season 7.
• October 3rd, 2024: Build updated for Season 6 and Vessel of Hatred.
• August 5th, 2024: Guide created.