Blighted Marrow

Damage is increased by 15% for each enemy Bone Spear passes through.

Bone Spear's damage turns into Poison.

Unlocked at level 7

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

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

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

Aura of Frailty

Becomes an aura that curses all enemies within 15 yards.

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

Unlocked at level 39

Blood and Bone

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

Unlocked at level 69