Frost Spikes

Leaves a frost patch that reduces the movement speed of enemies by 60% for 2 secs.

Bone Spikes' damage turns into Cold.

Unlocked at level 25

Crystallization

Each enemy hit has their attack speed reduced by 20% and your attack speed is increased by 3% for 3 seconds stacking up to 10 times.

Bone Spear's damage turns into Cold.

Unlocked at level 25

Devouring Aura

Becomes an aura that consumes all corpses within 15 yards to restore 11 Essence per corpse.

The range of this effect is increased by 50% of your gold pickup radius.

Unlocked at level 38

Potency

Increases your armor by 100% for 2 seconds after casting.

Unlocked at level 34

Blood and Bone

Now also creates a Simulacrum of Bone, but the duration is reduced to 10 seconds.

Unlocked at level 69

Harvest of Anguish

Bone Armor also increases your movement speed by 1% for each enemy hit.

Bone Armor's damage is turned into Cold.

Unlocked at level 48