The Whirlwind Barbarian relies heavily on Physical Damage and Attack Rating. Every increase in these stats you can manage is going to help. The most important thing is the Weapon. Obedience is a strong Runeword that is easily farmed, as well as the new Unbending Will Phase Blade.

A source of % Mana stolen per hit makes this build a lot more comfortable to play. In addition, Increased Attack Speed, Damage, Attack Rating, and Resistances are important. Make sure to cap out your Resistances because you are taking hits when spinning through packs of enemies. Smoke helps you in that task.

To keep your Mercenary alive, equip him with a Body Armor and Helmet with Resistances and Life. Insight is a pretty easy Runeword to find and farm that gives a great amount of damage and Quality of Life with Meditation. Hire the Might Aura Mercenary, to gain extra Physical Damage.

The Weapon Mastery depends on the Weapon used. In this example, we use Polearm Mastery for Obedience.

Put 1 Point into each of the following Skills:
1. finditem
2. Grim Ward
3. increasedspeed
4. naturalresistance
5. leap
6. leapattack

Max out the following Skills in this order:
1. Whirlwind
2. Polearm Mastery (Depends on your Weapon)
3. Battle Orders
4. Berserk

Allocate enough Stat Points into Strength and Dexterity to equip your gear. Put remaining Stat Points into Vitality.

The Standard variant of the Whirlwind Barbarian uses dual Grief Phase Blade providing up to +800 Damage. Absolutely nothing comes close for raw damage with these weapons.
Using Fortitude over Enigma is an option to increase your damage, sacrificing the mobility of Teleport. Highlord's Wrath and Gore Rider are great for additional x% Deadly Strike, increasing your chance of critical strikes, while Laying of Hands are great for the +x% Damage to Demons. Use Bone Break instead of Sharp Grand Charm of Maiming to enable farming of any monster.

Might Aura Desert Mercenary provides us with a significant boost to our Physical Damage attacks.
The Reaper’s Toll has a chance to cast Decrepify on striking, which slows your enemies down, increases any Physical Damage dealt to them, and even breaks Physical Immunities. Andariel's Visage and Fortitude Sacred Armor fill in everything else he needs, from damage to survivability.

The Weapon Mastery always depends on the Weapon used. In this case we use blade Mastery:

Put 1 Point into each of the following Skills:
1. finditem
2. Grim Ward
3. Battle Command
4. Battle Cry
5. increasedspeed
6. naturalresistance
7. leap
8. leapattack

Max out the following Skills in this order:
1. Whirlwind
2. blade Mastery
3. Battle Orders
4. Find Potion
5. Berserk

Allocate enough Stat Points into Strength and Dexterity to equip your gear. Put remaining Stat Points into Vitality.

With this variant you are using a 2 Handed Weapon with massive damage like Breath of the Dying War Pike.
Using Fortitude over Enigma is an option to increase your damage, sacrificing the mobility of Teleport. Highlord's Wrath and Gore Rider are great for additional x% Deadly Strike, increasing your chance of critical strikes, while Laying of Hands are great for the +x% Damage to Demons. Use Bone Break instead of Sharp Grand Charm of Maiming to enable farming of any monster.

Might Aura Desert Mercenary provides us with a significant boost to our Physical Damage attacks.
The Reaper’s Toll has a chance to cast Decrepify on striking, which slows your enemies down, increases any Physical Damage dealt to them, and even breaks Physical Immunities. Andariel's Visage and Fortitude Sacred Armor fill in everything else he needs, from damage to survivability.

Weapon Mastery always depends on the Weapon used. In this case, we use Spear Mastery:

Put 1 Point into each of the following Skills:
1. finditem
2. Grim Ward
3. Battle Command
4. Battle Cry
5. increasedspeed
6. naturalresistance
7. leap
8. leapattack

Max out the following Skills in this order:
1. Whirlwind
2. Spear Mastery
3. Battle Orders
4. Find Potion
5. Berserk

Allocate enough Stat Points into Strength and Dexterity to equip your gear. Put remaining Stat Points into Vitality.

Magic Find Whirlwind Barbarian uses Grief Phase Blade for damage and Last Wish Phase Blade with x% Better Chance of Getting Magic Items (MF) among its other solid stats. This is capable of most content with its damage and survivability.
Note: If you need to get back to town, we use the Scroll of Town Portal on the Belt. Use Fine Small Charm of Good Luck to increase your Magic Find even further.

For this variant we use the Act 5 Mercenary because we already have Might from Last Wish Phase Blade. The advantage is his fast Attack Speed that allows him to proc Decrepify from Lawbringer Phase Blade and x% Chance of Crushing Blow from Guillaume's Face. Survivability mainly comes from Fade provided by Treachery Sacred Armor.

This Skill Tree works the same as the Standard Weapon Mastery always depends on the Weapon used. In this case we use blade Mastery:

Put 1 Point into each of the following Skills:
1. finditem
2. Grim Ward
3. Battle Command
4. Battle Cry
5. increasedspeed
6. naturalresistance
7. leap
8. leapattack

Max out the following Skills in this order:
1. Whirlwind
2. blade Mastery
3. Battle Orders
4. Find Potion
5. Berserk

Allocate enough Stat Points into Strength and Dexterity to equip your gear. Put remaining Stat Points into Vitality.

The Uber Variant has lots of Damage Reduction (50%), Resistances, and Life. Prior to entering any of the Uber fights we proc Fade by standing in the fire next to the River of Flame Waypoint.
Use Whirlwind in small triangles to dish out the most DPS. The most impactful items for this build are Arreat's Face, Thundergod's Vigor for Absorb, Stormshield, and Blood Crafted Ring to fill the rest. Dracul’s Grasp and Last Wish allows you to cast Life Tap on striking, adding another layer of Life recovery. Use Bone Break instead of Sharp Grand Charm of Maiming to enable farming of any monster.

For this variant we use the Act 5 Mercenary because we already have Might from Last Wish Phase Blade. The advantage here is that his fast Attack Speed allows him to proc Decrepify from Lawbringer Phase Blade and x% Chance of Crushing Blow from Guillaume's Face. Survivability mainly comes from Fade provided by Treachery Sacred Armor. DON'T expect your Mercenary to survive Uber Tristram!

Weapon Mastery always depends on the Weapon used. In this case we use blade Mastery:

Put 1 Point into each of the following Skills:
1. finditem
2. Grim Ward
3. Battle Command
4. increasedspeed
5. naturalresistance
6. leap
7. leapattack

Max out the following Skills in this order:
1. Whirlwind
2. blade Mastery
3. Battle Orders
4. Battle Cry
5. Berserk

Allocate enough Stat Points into Strength and Dexterity to equip your gear. Put remaining Stat Points into Vitality.

This variant is what you want for survivability. We focus on having the maximum amount of Damage Reduction (50%) while stacking over capped resistances and Life. We also aim for 75% Chance to Block by adding enough Dexterity to reach this.
The most impactful items for this setup are Stormshield, Crown of Ages, Thundergod's Vigor and sometimes Verdungo's Hearty Cord. Dwarf Star or Wisp Projector can also be used for more Absorb. Don’t go too overboard with Defenses though. We all know Offense is the best Defense. Use Bone Break instead of Sharp Grand Charm of Maiming to enable farming of any monster.

We recommend the Might Aura Desert Mercenary as it provides us with a significant boost to our Physical Damage attacks.
The Reaper’s Toll has a chance to cast Decrepify on striking, which slows your enemies down, increases any Physical Damage dealt to them, and even breaks Physical Immunities. Andariel's Visage and Fortitude Sacred Armor fill in everything else he needs, from damage to survivability.

Weapon Mastery always depends on the Weapon used. In this case we use blade Mastery:

Put 1 Point into each of the following Skills:
1. finditem
2. Grim Ward
3. Battle Command
4. Battle Cry
5. increasedspeed
6. naturalresistance
7. leap
8. leapattack

Max out the following Skills in this order:
1. Whirlwind
2. blade Mastery
3. Battle Orders
4. Find Potion
5. Berserk

Put enough Stat Points into Strength to wear your gear, Dexterity to reach 75% Chance to Block, and the remaining Stat Points into Vitality.