Path of the Unfortunate

You were influenced by the Shadowfell to such extent that it manifests in your wrath, although you weren't entirely consumed by the negative presence of it, you have gained abilities that resemble the dark realm's inhabitants.

Gloom Presence

When you take this subclass at 3rd level, the emptiness and dreary aura of the Shadowfell echoes from you, making everyone around you uneasy. You gain proficiency in the intimidation skill, and can add your constitution modifier to intimidation checks.

Veil of Shadow

At 3rd level, your connection to the Shadowfell makes you more resistant to trickery and damage, you gain resistance to necrotic damage. In addition, you can add your constitution modifier to Wisdom saving throws.

Fueled by Shadow

at 3rd level, the dark energy of the shadowfell is empowering your strikes when you rage. When you hit a creature with a melee weapon attack while raging, you deal bonus necrotic damage equal to your barbarian level.

Shadow Walk

At 6th level, while you rage, your movement starts to resemble a Shadowspawn. When you move while raging, you instead hover, making you ignore difficult terrain. In addition, once per rage, instead of moving you can teleport to an unoccupied space within 30 ft of you, if there's a hostile creature within 5 ft of the space you teleported to, you attack him instantly, sacrificing your bonus action if you do.

Negative Pressure

At 10th level, the negative energy from the Shadowfell represses magic around you while raging. When you see a creature casting a spell within 60 ft of you, you can use your reaction to force the caster to make a wisdom saving throw against a DC equal to 8 + your proficiency bonus + your constitution modifier. Whether the creature succeeds or fails the save, the spell is wasted, however if the creature succeeds you take 6d6 psychic damage instead of the spell's effect.

Refusal of Death

At 14th level, the Shadowfell manifests completely in your rage, making you almost impossible to kill. When you are reduced to 0 hit points and not die instantly, you can make a melee weapon attack against a creature within 10 ft of you. On a hit, you regain a number of hit points equal to the damage dealt + half your barbarian level, sacrificing the rest of your turn. Every time you regain health using this feature, you gain 1 level of exhaustion, making your attack rolls, saving throws and ability checks have -1 for every level of exhaustion. If the attack misses, you instead fall unconscious with 1 failed death save.