I'm looking for opinions and suggested on this subclass variant that I whipped up for my group. In short, I have several players that love the aesthetic of the berserker barbarian and would like to play one, but hate how it compares to the other barbarian subclasses. So they asked me to take a look and see what I can come up with to make it better while keeping the risk vs reward for choosing to go into frenzy or not. So let me know what ya'll think needs to be changed and anything will help.

• Frenzy
  • Starting at 3rd level, you can go into a frenzy when you rage. If you do so, for the duration of your rage you can make the attack action 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.
• Mindless Rage
  • At 3rd 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.
• Unrelenting Endurance
  • Beginning at 6th level, when you finish a short rest, you can reduce your exhaustion level by 1. You can use this feature twice per long rest.
• Intimidating Strike
  • Beginning at 10th level, once per turn when you land a critical hit or kill a creature, each hostile creature within 30 feet of you must make a Wisdom saving throw (DC equal to 8 + your proficiency bonus + your Strength or Charisma modifier) or be frightened of you for 1 minute. Each frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. 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.
  • In addition, you also become proficient in intimidation skill if you don't already have it and your proficiency bonus is doubled for any ability check you make that uses intimidation.
• Ruthless Retaliation
  • Starting at 14th level, when you take damage from a creature, you can use your reaction to make a melee weapon attack against that creature if it is within 5 feet. If you are in a frenzy you may move up to half your movement towards that creature before making your attack.