Path of the highlanders

Many believe that highlanders dedicate their lives to the crafting of the perfect body. It is also believed that they live in isolation from society, trying to learn how to perfect their endurance strength and resolve to perform better in battle. It is known that following in the footsteps of highlanders grants warriors blessings in the battle field. Barbarians specifically start to demonstrate even more recklessness and raw strength. The barbarians that follow this path are always interested in testing their abilities. They do so by fighting and are always ready to leap into battle. The stories tell of barbarians challenging multiple enemies at once and being able to withstand the combat for longer periods, such is their raw endurance. Some stories talk about highlanders that perfected their endurance so much that time stopped affecting their bodies.

Superior bodies

When you aren't wearing armor, your AC is 10 + Strength modifier + Constitution modifier.

Reckless nature

When you hit an attack using the reckless attack feature, you can add damage to the damage roll equal to your barbarian level.

Battle cravings

You have advantage on initiative rolls, plus you can add half your proficiency bonus to your initiative roll a number of times equal to your constitution modifier. 

Timeless body

You don't suffer from the effects of old age. You naturally age slower and can not be aged by any magical means.

Soul extinction

While raging, as an action you let out a mighty roar. Each creature within 10 ft of you makes a Strength saving throw against a DC equal to 10 + your Constitution modifier. On a failed saving throw, each creature takes 6d8 force damage and is knocked prone. On a success, they take half as much damage and are not knocked prone. You can use this feature four times before taking a long rest. You regain all uses after a long rest.

Repeatetly using this feature takes a toll on your body. After two uses before taking a long rest roll a d20, on a 10 or less your rage ends. After three uses before taking a long rest, you gain a point of exhaustion. After four uses, you gain another point of exhaustion and can not rage anymore until you take a long rest.