Path of the Terror

Barbarians are known and feared for their rage. The Path of the Terror Barbarian is feared even more than other notable Barbarian Paths. They capitalize on this fear to devastating effect. 

When you choose this path at 3rd Level, work with your DM to create a terrifying origin. Some options include being enslaved by a demon, infected by a terrible disease, cursed by a powerful evil, becoming an awakened descendent of a Lovecraftian horror or something else that makes sense for your campaign. When you rage, you can choose to take on aesthetic traits of your terrifying origin. 

Prescence of Evil

When you rage, You take on traits from your terrifying origin. A number of creatures equal to your proficiency bonus +1 must make a dc 16 wisdom saving throw or become frightened of you until the end of your next turn. You can choose any creatures that can see or hear you. As an action while raging, you can choose 1 additional creature and have them make a dc 16 wisdom saving throw or become frightened. If a creature succeeds the wisdom saving throw, they are immune to the effect for 24 hours. 

In addition, you gain a +4 to Intimidation checks.

Frenzied Rage

Beginning at 6th level, you can’t be charmed or frightened while raging. If you are charmed or frightened when you enter your rage, the effect is suspended for the duration of the rage. Additionally, you can make a single melee weapon attack as a bonus action on each of your turns after this one.

Revenge

Starting at 10th level, when you take damage from a creature that is within 5 feet of you, you can use your reaction to make a melee weapon attack against that creature.

Advancing Evil

At 14th level, your rage becomes so terrifying that your opponents take extra damage from your melee attacks. Pick either psychic or necrotic damage. When you are raging, your attacks deal an extra 1d6 damage of the selected type. This damage increases to 2d6 if the creature is frightened of you.

Advancing Evil (Necrotic)

You choose Necrotic as the damage type for Advancing Evil.

Advancing Evil (Psychic)

You choose Psychic as your damage type for Advancing Evil.