For some barbarians, rage is a means to an end - that end being violence. Those who choose the Path of the Berserker, learned to focus their rage into an untrammeled frenzy. This allows berserkers to push their physical limits at the risk of their own health and well being. Due to this frenzy, berserkers are known to be an unstoppable force on the battlefield instilling fear and chaos to all who stand in their way.

Creator's Note: The intention of this homebrew is to improve upon the shortcomings of the official "Path of the Berserker" barbarian subclass while maintaining the fantasy of playing a berserker. If you have any questions about how I came to my conclusions for certain features just ask, and I'll gladly give my reasoning.

Frenzy

3rd-level Path of the Berserker feature

You can go into a frenzy when you rage. If you do so, for the duration of your rage you can make an single attack as a bonus action on each of your turns. When your rage ends, you must succeed a DC 17 Constitution saving throw or you suffer one level of exhaustion.

Each time you use Frenzy after the first, the DC increases by 2. The DC resets to 17 when you finish a long rest.

Imposing Posturing

3rd-level Path of the Berserker feature

Your physical stature aids you when intimidating others. Whenever you make a Charisma (intimidation) check, you gain a bonus to the check equal to your Strength modifier (minimum of +1). You also gain proficiency in the intimidation skill if you don't already have it.

Unrelenting Rage

6th-level Path of the Berserker feature

While raging you gain resistance against psychic damage and cannot be charmed or frightened. If you are charmed or frightened when you enter your rage, the effects are suspended for the duration.

In addition, whenever you finish a short rest, your exhaustion level, if any, is decreased by 1.

Intimidating Presence

10th-level Path of the Berserker feature

You can use your action to frighten someone with your menacing presence. When you do so, choose one creature that you can see within 30 feet of you. If the creature can see or hear you, it must succeed on a Wisdom saving throw (DC equal to 8 + your proficiency bonus + your Strength or Charisma modifier) or be frightened of you until the end of your next turn. On subsequent turns, you can use your action to extend the duration of this effect on the frightened creature until the end of your next turn. This effect ends if the creature ends its turn out of line of sight or more than 60 feet away from you.

If the creature succeeds on its saving throw, you can’t use this feature on that creature again for 24 hours. If you use this feature while raging and a hostile creature fails the saving throw, your rage does not end early for ending your turn and not attacking a hostile creature or taking damage since your last turn.

Ruthless Retaliation

15th-level Path of the Berserker feature

When you take damage from a creature, you can use your reaction to make one weapon attack against that creature if you are within 5 feet of it. If you are raging, you can move up to half your movement towards that creature before making your attack.