Path of the Shadowfiend

The Shadowfiend is a menace when it comes to the battlefield. The way they came to be is either by falling into the void or making a deal with the Shadowfell deity. No one knows for sure how these fiends come to the battlefield but all they do know is that whenever you come up against them in a fight they are sure to lose. 

Fiendish Hide

Starting at 3rd level, your skin becomes a thick hide while you rage. While you are raging, you gain resistance to Cold, Lightning, and Poison damage.

Shadowform

Starting at 6th level, your form becomes wispy and filled with shadows while you rage. While you are raging, you can use a bonus action to teleport to an unoccupied spot that you can see within 30 feet of you. Once you use this feature, you can not use it again until you rage again.

Nightwalker Strikes

Beginning at 10th level, your fury is honed to a merciless precision. While raging, when you take the Attack action and successfully hit a creature with two attacks using a melee weapon, you can immediately use your Bonus Action to make one more attack with the weapon against the same creature. You may use this ability a number of times equal to your Proficiency Bonus and regain all uses of it when you finish a long rest.

Dimensional Lock

Beginning at level 14, while you're raging, your presence disrupts extradimensional access.
When a creature within 10ft of you tries to teleport or leave their current plane, they must succeed on a Wisdom saving throw (DC 8+Strength modifier+Proficiency Bonus), or the teleport or plane shift fails.