Superior Path of the Berserker

For some barbarians, rage is a means to an end – that end being violence. The Path of the Berserker is a path of untrammeled fury, slick with blood. As you enter the berserker's rage, you thrill in the chaos of battle, heedless of your own health or well-being.

Frenzy

Starting when you choose this path at 3rd level, you can choose to go into a frenzy when you rage. If you do so you gain all the benefits of rage and for the duration of your frenzy you can make one additional melee weapon attack as part of your attack action on each of your turns after this one. Additionally at the start of your frenzy you gain temporary hit points equal to your barbarian level times two and during your frenzy you are not affected by any levels of exhaustion you may have. When your frenzy ends, you must make a Constitution saving throw DC = 8 and every subsequent use of this feature increases the DC by 2 or suffer 1 exhaustion point. When you finish a long rest, the DC resets to 8; any temporary hit points gained are lost at the end and you once again suffer the effects of exhaustion levels.

Additionally at 11th level, the DC for the frenzy feature resets on a short rest instead of a long rest. 

Mindless 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 effects are suspended for the duration of your rage.

Tireless Endurance

Starting at 6th level, Your body is able to recover from fatigue to the point its second nature, whenever you finish a long rest you are able to reduce your exhaustion level, if any, by 2 instead of 1.

Intimidating Presence

Beginning at 10th level, you can use your action to Frighten creatures with your menacing presence. When you do so choose a number of creatures equal to your Str mod that you can see within 30 ft of you. If the creature can see or hear you, they must make a Wisdom saving throw (DC = 8 + Proficiency + STR Mod) or be frightened until the end of your next turn. On subsequent turns, you can use your bonus 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 line of sight or more than 60 ft away from you. If the creature succeeds on its saving throw, it can’t be frightened using this feature for 24hrs. Creatures immune to fear or the frightened condition are not affected by this.

Warrior's Endurance

Starting at 10th level, You have learned to relax your body to the point that you are able to recover from fatigue faster than most. Whenever you finish a short rest you are able to reduce your exhaustion level, if any, by 1.  

Retaliation

Starting at 14th level, When you or an ally within your weapons reach takes damage, you can use your reaction to make a weapon attack against that creature. Additionally if you critically hit with the attack, you can make another attack against the same creature. This feature is not repeated if you score a critical hit with the second attack.