A barbarian who has been task by it clan with the duty of carrying out torture, and then later death sentences to all who has broke the law of their tribe. Most executioner relay on using complex, less bloody methods like hangman, noose, or pyre to their work. But this barbarian, who only need it brute strength and a deadly two-handed weapon, goes for a more simple, gore-style method of beheading people. But a course, the Executioner doesn't only work during execution site; this barbarian can take it skill out to the battlefield, where it can use the skill to slice-off the head or even torso of an, to spread fear and horror upon the enemies moral, while helping achieve victory.

Executioner Rage

At 3rd level, you unleash the full rage of being an Executioner, putting your full strength into your heavy weapon to behead your enemy. While raging, you gain the following bonuses:

• -For the duration of your rage, you can make a single melee weapon attack as a bonus action on each of your turns, though only for your heavy, two-handed weapon.
• -You have advantage on saving throws against being frightened.
• -A melee weapon does one extra die of its damage when you hit the target with it (included in the attack).
• -When you hit an enemy with an opportunity attack, the target must succeed on a DC 15 Strength saving throw or be knocked prone.

The Beheader

At 3rd level, you wield your trusting weapon that is used not only to kill enemies, but to also to behead them in an gruesome way. You can only attune a weapon, whether non-magical or magical, that is both a two-handed weapon and deals slashing damage, in order for it to becomes the "Beheader". You can only have one weapon attuned at a time. You become proficient in wielding either Glaive, Halberd, Greataxe, and Greatsword. You gain an extra 1d4 slashing damage when wielding the Beheader. Upon attacking an opponent that is either frightened or is knocked prone on the ground, your attack gain an extra damage equal to 1d6 + half your barbarian level.

Bloody Judgement

At 6th level, ending a person life give you the sudden rush of adrenaline and rejuvenation to continue on with the next execution. Whenever you killed an enemy while raging,  you regain hit point equal to 1d6 + your constitution modifier. 

Decapitation

Beginning at 10th level, the mere sight of you beheading a person will cause those around you to scream in horror. When you reduce an enemy health to zero with your weapon, you will immediately behead that enemy and let his body fall on the ground headless. Enemies that are with 20 feet of you must, if they have seen this act, must succeed on a Wisdom saving throw (DC equal to 10 + your proficiency bonus + your Charisma modifier) or become frightened of you until for the duration of two rounds. You can also used your bonus action to move half the speed, though only for the purpose to chase down a frighten enemy and nothing more. This effect ends if the creature ends its turn out of line of sight or more than 60 feet away from you.

Pendulum Guillotine

At 15th level, you can now muster the strength to make a fury of long, heavy swings against your foes like a pendulum, in the attempt to behead them in a row. As an action, you can make a four, powerful strike against a single target or multiple enemies that is at least 5'ft from you (two attacks against two, one attacks against four). Each swing attack against an enemy will be 2d8 slashing damage ( four equal 8d8). Once used, you need to get a long-rest to gain back the ability.

Final Execution

As you are struck down by a deadly foe, your mind close to fading away, yet your body moves on it own, trying to finish the job given to you as Executioner for one last time. When your health is brought down to zero and an enemy is within melee range from you, you can used an reaction in the attempt to hit your attacker with one chances. If you success in hitting the target, the damage roll become double + your Strength modifier. If the enemy dies from your reaction, you immediately regain only one hit point and stand back on your feet. You can only used this ability once, and need to spend a long rest to regain it.