Berserker is one of the two available skill trees for the Hatchet Mastery in New World. Berserker abilities mainly focus on boosting the player's melee attacks and increases both their speed and the player's. Hatchets mainly benefit from Strength, but Dexterity also contributes although on a secondary level.
All Berserker Tree Abilities in New World
Berserker Active Abilities

Feral Rush
A sprinting melee attack that causes the player to leap forward, hitting twice. The first hit deals 115% weapon damage and the second deals 130% weapon damage.
Cooldown: 12 seconds.
Upgrades:
Dispatch: If target is below 30% health, Feral Rush deals 20% more damage.
Crippling Strikes: If Feral Rush hits a target in the back, it causes Root, immobilizing target for 2 seconds.

Berserk
Triggers a Berserk Mode that increases all attack damage by 20% while active. Berserk Mode will be active for 15 seconds.
Taunt Gem Compatible: If you have a Carnelian gem equipped in your hatchet, this ability cause a 8s taunt to all enemies within 8m. (Taunt causes monster to focus only on you)
Cooldown: 30 seconds.
Upgrades:
On The Hunt: Increases movement speed by 20% while in Berserk Mode.
Berserking Refresh: While Berser is active, gain a portion of your health back every 5 seonds. Amount of health gained increases the by how long Berserk is active.
Berserking Purge:Triggering Berserk removes all Crowd Control effects (Stuns, Slows, Roots) from the player.
Uninterruptible Berserk: While in Bersek, your attacks are uninterruptible and you can't be staggered.

Raging Torrent
Perform four fast attacks, each dealing 90% weapon damage. Cooldown: 15 seconds
Upgrades:
Aggressive Approach: Hitting a target with Raging Torrent grants Haste, increasing movement speed by 20% for 6 seconds.
Final Blow(Hatchet): Press Light Attack at the end of Raging Torrent to deal a final attack dealing 120% weapon damage.
Berserker Passive Abilities

Enraged Strikes
If target is below 30% health, Light and Heavy attacks deal 20% more damage.

Against All Odds
Increase base damage by 10% for every enemy within 5 meters of player.

Frenzied Purge
When hitting an enemy while your health is below 30%: Remove all Bleed, Burn, and Poison DoT effects from the player. 60 second Cooldown

Accumulated Power
After 3 successful light attacks against the same target: gain Empower, granting a 30% damage increase for 3 seconds of until the next attack.

Relentless Fury
After a successful Heavy attack: gain Empower granting a 30% damage increase for 3 seconds oo after 4 stacks.

Fortifying Strikes
Hitting the same target with 3 light attacks grants Fortify, increasing damage absorption by 15% for 3 seconds.

Desperate Refresh
All cooldowns are reduced by 2% when hitting an enemy with an attack while your HP is below 30%.

Defy Death
Upon receiving lethal damage, you will avoid death and instead be reduced to 50 HP while gaining invulnerability for 4 seconds. Cooldown: 60 seconds.