Berserker

Berserkers walk armor-less into battle and are as crazed as dogs or wolves and as strong as bears or bulls. They bit their shields and slew men in droves while they themselves were harmed by neither fire nor iron.
A tall human swordsman strides through a blood-soaked battlefield, wielding that which was too big to be called a sword, massive, thick, heavy, and far too rough. Indeed, it was a heap of raw iron and of all men who walked that battlefield that day, none could doubt that mans strength or that weapons impracticality as he dyed its black steel crimson.
Despite a commander's best efforts, no magic of the Weave, nor blade made of man could stop the indomitable goliath that broken the will of all men who dared walk before him, as if he was an avatar of war itself, he warped what was the twisted stench of death and strive, into a one-sided conquest through his immeasurable fortitude and strength, for he alone was the Hell walker.
In the darkness of the forest, an enemy scouting party stops, disturbed by the slender figure of a man who blocks their path, his unblinking eyes watching them like a wolf of the night. Granted power through the teachings of Fenrir, his movements are fast and unrelenting, as he cleaves through the unit like the beast himself. In his ravenous bloodlust he found no satisfaction; and with rushing blood he scoured the forest of those who had fled, their wounds carving a path to them through the dense foliage and sealing their inescapable fates.
As if possessed by the Æsir themselves, his iron will remain steadfast against the hellfire that threatened to consume him, shielding the weak and defenseless with his own body as the flames seared his flesh and bone, but it was then when the fires subsided that the man marched towards the servants of hell, hunting them with barbarous cruelty as if he had passed through the divide as none but demon had before. A Berserker makes his place in any battle, dying a thousand times and walking out alive, surviving wounds and attacks that would kill most only to come back the next day in search of his next fight. Their insatiable desire for battle leads them to become fierce nigh-unkillable soldiers of war, that embody some of the most dangerous beings of the Norse pantheon, primary, Fenrir and the Æsir. All those who face a Berserkers wrath be warned, for their presence and will alone break even the most fearless of men...

Creating a Berserker

A Berserker can live multiple types of life. They can make their place in society and civilization as mercenaries or hired hands, they can live a life in the wild as hunters or nomads. They usually live a life of vigorous training and constant states of battle.
Quick Build
You can make a Berserker quickly by following these suggestions. First, pick Constitution or Strength followed by the other and then pick Charisma. Lastly, choose either the Soldier or the Outlander as your background.

Class Features

As a Berserker you gain the following class features.

Hit Points

Hit Dice: 1d12 per Berserker level
Hit Points at 1st Level: 12 + Constitution modifier
Hit Points at Higher Levels: 1d12 (or 7) + Constitution modifier per Berserker level after 1st

Proficiencies

Armor: shields
Weapons: Simple weapons, martial weapons
Tools: None

Other Goodies

Saving Throws: Strength, Constitution
Skills: Choose two from Athletics, Acrobatics, Insight, Intimidation, Perception, and Survival

Equipment

You start with the following equipment, in addition to the equipment granted by your background:
Option 1 - one simple weapons and a shield or (b) one martial weapons Option 2 - four javelins or (b) one martial weapons Option 3 - a explorer's pack or (b) a dungeoneer's pack a trophy from a slain adversary If you are using starting wealth, you have 4d4x10gp in funds.

Berserker Features

Whenever this class refers to a Berserker save DC you use the formula below to calculate it.
Berserker save DC = 8 + your proficiency bonus + your Strength modifier
Unarmored Defense
Starting at 1st level, while you are not wearing any armor, your Armor Class equals 10 + your Constitution modifier + your Charisma modifier. You can use a shield and still gain this benefit.
Fighting Style
Also at 1st level, you adopt a particular style of fighting as your specialty. Choose one of the following options that best suits your Berserker nature:
Great Weapon Fighting
When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.
Two-Weapon Fighting
When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.
Obstruction
Before the outcome of the roll is determined, you can use your reaction to gain a +2 bonus to your Armor Class against that attack, potentially causing the attack to miss. You must have a weapon with the heavy property or shield in your hand to use this.
Protection
When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.
Strength from Pain
What doesn't kill you makes you stronger. This is the creed of all berserkers and you know it well. Starting at 2nd level, when a creature deals damage to you, you can use that pain to fuel your combat prowess. On your next turn, as a bonus action, you can deal additional damage on your next successful melee attack equal to half the total damage that creature would have delt. For example, if an opponent rolls a 12 on their greatsword strike and adds 4 due to their Strength modifier, you can deal 8 additional damage with this feature, regardless of resistances. This damage can only apply to the target that dealt that damage to you. You can use this feature a number of times equal to your Constitution modifier and you regain all expanded uses once you finish a long rest.
Berserker's Path
At 3rd level, a Berserker defines his call to battle by either the Path of Fenrir, becoming as savage as Fenrir, the great wolf that will slay the even mighty Odin come Ragnarök, or they follow the Path of the Æsir, embodying the mighty Norse Gods whose wars can be felt across the nine realms and whose power keeps the realms in balance.
Ability Score Improvement
When you reach 4th level, and again at 8th, 12th, 16th, and 19th level, you can increase one ability score of your choice by 2, or you can increase two ability scores of your choice by 1. As normal, you can’t increase an ability score above 20 using this feature.
Extra Attack
Beginning at 5th level, you can attack twice, instead of once, whenever you take the Attack action on your turn. The number of attacks increases to three when you reach 13th level in this class.
Rip and Tear
Starting at 6th level, all forms of defense feel the effect of your onslaught. Whenever you successfully make two melee weapon attacks against the same creature on the same turn, the target receives a -1 penalty to their Armor Class. This only applies if the target posses a form of armor whether it be natural or otherwise. This penalty can stack, to a maximum penalty equal to half your proficiency bonus rounded down. A creature with natural armor is no longer under the effect of this feature when they are healed to their hit point maximum. Magic armor is unaffected by this feature unless the weapon damage is also magical. Finally, this feature cannot reduce a target below 10 + the targets Dexterity modifier.
Battle Hardened Endurance
Starting at 8th level, when you make a Constitution saving throw and the result is less than your Constitution score, you can use that score in place of the total. You may do this a number of times equal to your proficiency bonus. You regain expanded uses of this feature when you complete a long rest.
Breath of Battle
You live, breathe, and thrive in the heat of combat. Starting at 10th level, you have advantage on your initiative rolls.
Intimidating Presence
Starting at 13th level, your presence alone is enough to break both man and monster, triggering their most primal instinct, fight or flight. You gain proficiency in the Intimidation skill. If you are already proficient with the Intimidation skill, you may add double your proficiency bonus to the check, instead of your normal proficiency bonus. In addition, when you make a Intimidation check against a creature within 30 feet you may attempt to instil fear in the target creature, who must succeed on a Wisdom saving throw against your Intimidation check or becoming frightened of you for one minute. A frightened creature may repeat their save at the end of their turn, ending the condition on a success. You may intimidate creatures this way a number of times equal to your Charisma modifier and regain all expanded uses when you complete a long rest.
Unyielding Body
Starting from 15th level, your Strength score, your Constitution score, and your hit point maximum cannot be reduced. In addition, anytime you come under the effect of exhaustion you can treat it as one level less then it actually is.
Unbreakable Will
Your experience on countless battlefields has made you as wise as you are strong, especially when confronting some of the most potent of magical effects. At 17th level, you gain proficiency in Wisdom saving throws.
Ragnarök
The final struggle of a dying beast is enough to shatter even the most impossible limits. Starting from when you reach 20th level, when you gain a failed death save or are outright killed, you may immediately stand up if prone and make a single attack, the call of Ragnarök demanding one final blow. This attack gains a range of 120 feet, advantage and deals its normal damage plus the value of your Blood Pool before you were downed or the number of temporary hit points you gain from entering your warpath. Whether it is the strength of the god behind your last blow, or the hatred of the great wolves, the bones and muscles in your body shatter and tear, your form collapsing as you, fall prone, and die. Any magic that would bring you back life does so, however, you are brought back with six levels of exhaustion, your body, mind, and soul pushed far past what any normal mortal would be capable of.