Path of calm fury

You have learned to focus your rage inward, powering it with cold, focused hatred rather than passionate anger. Your rage is a tool that you have honed to a razor edge, harnessing it dispatch you foe with haste, efficiency and shocking brutality. Most calm fury barbarian actually grow more quiet when they rage, with only a smolder in their eye indicating their shift to a merciless killing machine.

Fighting style

Starting at 3rd level, your more restrained approach to rage leaves time in your training to master a particular fighting style. You learn one of the fighting style available to fighter at first level.

Rage burst

When you choose this path at 3rd level, you can choose to focus your ongoing rage into a single, massive manifestation of its power that immediately ends it. You can use one of the following power while you rage:

-Focused strike: After you hit with a melee weapon attack, you can choose to roll the weapon's damage dices 2 additional times and add the result to the damage rolls. At 10th level you can roll the damage 3 times, 4 times at 15th level and 5 times at 20 level. After using this ability, your rage immediately ends.

-Ignore pain: When a creature hits you with an attack that deals slashing, piercing or bludgeoning damage while you are raging, you can use your reaction to gain immunity to these damage types until the start of your next turn. At the start of your next turn, your rage ends.

-Adrenaline burst: When you fail a strength check or strength saving throw while you are raging, you can choose to succeed instead. You cannot use this if you would have still failed on a natural 20 on the die. At the start of your next turn, your rage ends.

You can use this feature a number of times equal to your proficiency bonus and regain all expended use after a long rest.

Smoldering gaze

Starting at 6th level, your internalized rage unsettles people you interact with. You can add your rage damage bonus to intimidate checks.

Focused hatred

Beginning at 6th level, whenever your rage begins, you can designated a creature you can see. Until your rage end, you add your rage damage bonus to your AC and saving throws against attacks and effect that originate from that creature. 

If that creature drops to 0 hp while the rage you used to target it is still ongoing, you can use a bonus action on your turn to designate a new creature as the target.

in addition, if you would fail a save against an effect caused by the target of this ability, you can choose to succeed instead, but you rage immediately ends. You can do so a number of times equal to your proficiency bonus and regain all expended use after a long rest.

Sustaining rage

Beginning at 10th level, you can tap into your inner fury to sustain you through pain and injury. While you are not raging, you can use you action to expend one of your uses of the rage ability to roll a number of d12 equal to half you barbarian level. You regain hit point equal to the amount rolled + your constitution modifier. Until the start of you next turn, you gain the damage resistance and saving throw bonus granted by your rage. You are, however, not considered to be raging while those abilities are active.

You can use this feature a number of times equal to your proficiency bonus and regain all expended use when you finish a long rest.

Always angry

Starting at 14th level, even when you are not raging you gain some of you rage's benefit.

-Once per round, when you make a strength check or strength saving throw, you can choose to gain advantage.

-Once per turn when you it with a weapon attack, you can add your rage damage bonus to the damage roll.

-After you are hit with an attack that deals bludgeoning, piercing or slashing damage, you can use your reaction to gain resistance to those damage types until the ends of the current turn.

In addition, When you finish a short rest with less than 3 uses of the rage ability remaining, you can regain one use of it. At 20th level, when you finish a short rest, you can regain 1 use of either Rage burst, the limited part of focused hatred or sustaining rage.