Path of Possession

Finding a cursed weapon, or a cursed item, or cursed family heirloom, the Barbarian gains an Ethereal boon that allows them to use Eldritch powers on the battlefield. These powers range from Cursing enemies, to Haunting enemies, to even utilizing a ghostly Incorporeal Stride. This gives the Barbarian an even mix of extra radiant or necrotic damage and movement.

Ethereal Curse

Starting when you choose this path at 3rd level, you can Curse someone with your Ethereal powers. As a bonus action, you may select a target within 30 feet and Curse them. While Cursed, you may use another bonus action to add 1d6 additional damage to the target every time that you attack with a Melee Weapon. The additional damage may be considered either Radiant or Necrotic. The die turns into a d8 at 5th level, a d10 at 10th level, and a d12 at 15th level. The target remains cursed for 1 minute, or until they die. You may use this feature as many times as your Constitution Modifier.

Haunting Step

Beginning at 6th level, you may teleport yourself adjacent to a successfully Cursed target, or you may swap locations with a willing target using a bonus action. You may use this feature as many times as your Constitution Modifier per long rest.

Incorporeal Stride

Beginning at 10th level, while raging, you gain a flying speed of half your normal walking speed, and gain the ability to walk through walls. Moving through walls ins an exhausting task, you can only move through 5 cumulative feet of obstacle. Doing so also ends your Rage. If you end your Rage or run out of distance while in an obstacle, you appear in an unoccupied spot from the direction in which you entered the obstacle. You also take pure damage equal to twice your Barbarian level. You may use this feature as many times as your Constitution Modifier per long rest.

Doom Strike

Starting at 14th level, you may use your action to throw your cursed weapon at a target making a ranged attack. if the ranged attack hits, you may instantly teleport yourself to the target claiming your weapon that cleaved itself into your enemy. If the ranged attack missed, you may use a bonus action to call the weapon to fly back into your grasp. If the target was cursed before they were hit, they take twice the Curse damage. If the target wasn't cursed before they were hit, you may automatically use Ethereal Curse without expending a charge, and have it take the double Curse damage. You may use this feature as many times as your Constitution Modifier per long rest.