Mauler is one of the two available skill trees for the Great Axe Mastery in New World. Mauler Abilities mainly focus on crowd control and Area of effect abilities. Great Axes benefit from Strength.
All Mauler Tree Abilities in New World
Mauler Tree Active Abilities

Whirlwind
Spin attack dealing 50% weapon damage to all nearby foes. If you hit a foe spin again(Max 4 spins) You can move while spinning. This attack cannot backstab. This attack has Grit.
(Grit prevents you from being staggered by incoming attacks)
Cooldown: 25 seconds
Upgrades:
Gusting Winds: Whirlwind's maximum number of rotations is increased to 7.
Unending Winds: Movement speed during Whirlwind increased by 50%.
Surrounded:If you have 3 or more enemies around you, Whirlwind deals 30% more damage.

Maelstrom
Fast-spinning attack that pulls enemies closer to you and deals 110% weapon damage. Cooldown: 20 seconds.
Upgrades:
Storm's Reach: Extends the reach of Maelstrom's pull effect by 50%.
Absorb: Consums all projectiles while Maelstrom is active.
No Reprieve: Maelstrom does an extra spin attack that pulls in foes and deals 110% weapon damage.

Gravity Well
Throw your axe to create a vortex that pulls foes towards its center for 3 seconds. Ends with a damaging Burst 125% weapon damage. Range: 10 meters. Cooldown: 30 seconds.
Upgrades:
Crowded Well: Increase burst damage by 10% for each foe caught in the vortex.
Unyielding: Allies gain 20% Fortify while standing in your well. (Fortify reduces damage received)
Mauler Tree Passive Abilities

Mauler's Resolve
If you get hit while holding a Great Axe while below 50% Health, gain 40 Stamina. Cooldown: 20 seconds.

Gravity
After you cause a pull, your foe is rooted for 0.25s.

Center of Attention
While holding a Great Axe, gain 10% damage while 3 or more foes are within 4 meters.

Heavy Pull
Heavy Attacks with a Great Axe pull foes closer to you.

Enduring Strike
Adds Grit to Great Axe Heavy Attacks, and grants a 20% damage reduction while the Heavy attack Grit is active.
(Grit is an added stagger resistance that stops attacks from being interrupted by reactions)

Revenge
When you block an attack with a Great Axe, gain 5% damage for 5 seconds. (Max 3 stacks)

Crowded Protection
While holding a Great Axe, gain 10% damage absortion while 3 or more foes are within 4 meters.

Mauler's Fury
Great Axe attacks increase damage by 3% for 3 seconds. (Max 10 stacks)