Path of the Dark Influence

The ferocity of your rage has attracted the gaze of an ancient being. This could be a blood thirsty daemon calling you to be their champion, a spirit of the untamed wilds asking you to stop encroaching settlements and protect their lands. Work with your DM to find an entity that works for your campaign and setting.

 Note: a lot of these can and should feel similar to a warlock patron or clerics deity. The entity does not need to be as defined as that though. 

Dark Influence

Your rage taps into a primal/otherworldly power source 

You have a number of dark influence dice equal to your proficiency + CON modifier. Dark influence die start as d4s. A dark influence die is expended when you use it. You regain all of your expended dark influence dice when you finish a long rest.

At levels 6, 10, and 14 the dark influence die increases to a d6, d8, and a d10

Additionally you gain proficiency in your choice of Arcana, Nature, or Religion

Dark Fury

At 3rd level, the dark gods bless your fury and channel their will threw you. While you’re raging, after hitting an enemy with a melee attack you may expend 1 of your dark influence die to deal extra damage. The extra damage is necrotic or radiant; the extra damage from this strike heals you for the same amount.

Dark Guidance

Begining at level 6 you now know the cantrip Guidance.  To cast guidance you must expend 1 Dark Influence Die.  If you have proficiency in that skill granted by this subclass you may roll your Dark Influence Die and use that result instead. 

Darkness Presence

At level 10 as a reaction, when raging, after an ally has been hit within 30 ft of you, you may spend 1 Dark Influence die to place yourself between the ally and the attack taking the damage instead.  The damage is reduced by the result of the roll.

Desperate Hope

Beginning at 14th level, you have learned to channel all of the dark power given to you into one powerful attack.

As a bonus action, while raging, on your turn you may expend all remaining Dark Influence dice to empower your blade until the end of your next turn. While empowered the next melee attack that hits an enemy will do an additional 1d12 per die expended.  Once this attack hits the weapon is no longer empowered and you are no longer raging.  You can not enter rage until you take a short rest