Level 1: Chill Soul - Karsh steals the essence of life from his enemies with every blow and is healed for 20% of the damage. All nearby enemies are 20% slower. (Passive)
Level 3: Shadow Step - Karsh walks on the path of death and teleports himself to the selected location. Enemies at the destination are temporarily paralyzed with fear. Left click on target area.
Level 5: Entrance to the Crypt - Karsh summons a Barrow which can be used by Barrow Wights as a tunnel network between barrows. Left click on target location.
Level 7: Voice of the Wight - Enemies in the area of the selected crypt lose 50% of their damage for 10 seconds and run away in fear after that. Left click on allied Barrow.
Level 10: Soul Thief - The whispering dread of Angmar steadily withdraws the light of life from his victims. Enemy units nearby are permanently damaged and transfuse their health to Karsh. Karsh is slowed down by 50% for the duration of this ability. Left click to activate.
Karsh can receive the following upgrade:
Might of the Witch-King - Karsh is healed by 75% of his dealt damage.
This upgrade can be applied to him through the Witch-King's ability Might of the Witch-King.