Path of the Rift

There is a place, located between the planes which holds all of reality together. It is called the rift and some barbarians have been trained harness this rift and gain strength and power from it's infinite force. These "Riftwalkers" are a special type of brute that use the potency of their rage to empower their attacks and their movement to become terrors to behold on the front lines of the battlefield. When a Riftwalker enters the fray of battle the whole scope of the fight changes, the Riftwalker can go where he likes and attack who he likes. This unstoppable powder keg of rage can only be stopped by an overwhelming force and even then it will almost be a fair fight, for them.

Rift Walker

Starting at 3rd level, while enraged, you tear a rift in your wake which allows you to push creatures away from you with your movement up to 5ft away per creature. This feature effects only creatures of one size larger than yourself. These enemies may not take attacks of opportunity if you continue by unless their weapon has the reach property.

Enduring Chasm

Upon reaching 6th level, you have the fury of the rift burning inside you. You may now choose to expend a rage slot during an attack to change all damage dealt to necrotic damage. You regain HP equal to half of the damage dealt. You may not gain excess HP as temporary HP. You can use this feature after a roll but before you know the result. 

Additionally, you are now resistant to force damage.

Rift Herald

At 10th level, your area of influence increases dramatically as you wield the rift’s power. While enraged, you have a reach of 10ft, weapons possessing the reach feature will increase this effect further. Any enemies that exit your space of 10ft are now eligible for an attack of opportunity and on a successful attack the target must make a Constitution Saving Throw with a DC equal to your barbarian level. On a failed save the target becomes stunned until the start of their next turn and may not progress further on their current turn.

Herald’s Doom

At 14th level your connection with the rift has now made you a terror on the battlefield. As an action, you may choose to embrace the rift and teleport to a place within 5 feet of a creature of your choice up to a range of 60 feet of you. Immediately after you use your Herald’s Doom, each creature of your choice that you can see within 15 feet of you takes necrotic damage equal to twice your barbarian level and you are healed for the same amount. The effects of this feature ignore resistance to necrotic damage but not immunity.

You may use this feature once and regain use of it by taking a long rest.

Unbreakable

Starting at level 14, your bond with the rift is now permanent. You gain the following effects only while you are enraged. 

-You have advantage when rolling against being grappled

-You cannot be knocked prone by any means other than falling

-Other creatures may not move you without your permission. (Example shield bash, shove, grasp of hadar, repelling blast)

-You are now immune to force damage while enraged