Path of the Disciplined Soul

You have learned to channel your rage inwards, so as to avoid making mistakes or lapses of judgement. You got more out of it than you bargained for, however. Many barbarians of this path are former monks, angered by corrupted monasteries and false faiths they were tricked into believing. Many others are druids, fed up with the callousness of humanity towards nature. Druids who bottle this rage utilize all wood or rock versions of traditionally martial weapons. This is not always the case.

Internalized Rage

When you channel your inner rage, you are capable of concentrating on spells while raging in return for the loss of one of your damage resistances. Each time you rage, the DM will decide which damage resistance you forego. 

Heightened Combatant

Your ability to dampen your bloodlust has allowed you to channel it inter a sort of hyper awareness. You can now add your Wisdom modifier to your unarmored defense. Additionally, you can add your wisdom modifier to your damage rolls.

Overflowing Rage

Your internal rage has awoken a dormant element within you. Choose an element between ice, fire, lightning, thunder, radiant, necrotic, force, or acid (or roll a d8, your choice). You may pick two 4th level or lower spells out of the Sorcerer and Wizard spell list, according to the element you chose.  Additionally, add an extra damage die of your weapon of your chosen type (Example: Timmy picked fire and his barbarian wields a greataxe, so he will now deal 1d12 slashing damage, and another 1d12 fire damage). At 14th level, you may pick two more spells, now 5th level or lower, and add another extra die.

Additionally, you gain the ability to cast a cantrip, related to your chosen element, at will. They level up with you as the cantrip descriptions say.

Ice - Chill Touch (But it's cold damage. Also, the target loses its reaction. Hit points are unaffected besides the obvious damage.)

Fire - Green-Flame Blade

Lightning - Shocking grasp

Thunder - Booming Blade

Radiant - Sacred Flame

Necrotic - Chill Touch (as the description says for the actual spell)

Force - Sword Burst

Acid - Primal Savagery

Acid

You have chosen acid as your element.

Fire

You have chosen fire as your element.

Force

You have chosen force as your element.

Ice

You have chosen ice as your element.

Lightning

You have chosen lightning for your element.

Necrotic

You have chosen necrotic as your element.

Radiant

You have chosen Radiant as your element.

Thunder

You have chosen thunder as your element.

Resilient Rage

Your tenacity and inward rage drives you to overcome outside influence. You have half proficiency on saves against being charmed or frightened. You also gain resistance to psychic damage.