Shieldbiter

Shieldbiters are based on the concept of the archetypal shielded barbarian, such as a Celtic berserker. Shieldbiters utilize a special battlecry, war paints, and aggressive shield-fighting techniques.

Battlecry

At third level, whenever you rage, select an enemy that can hear you. You bellow a mighty roar. That enemy makes a wisdom save against your constitution score. On a successful save, they are taunted, and have to spend the duration of your rage attacking you. On a failed save, the target is frightened, and can recover after leaving your line of sight and passing a wisdom check.

Warpaint

Beginning at sixth level, you may select and apply a type of warpaint during a short or long rest. Mixing a new batch of warpaint requires 5gp worth of herbs and dyes. Different warpaints have different effects:

Woad: While applied, this indigo warpaint causes you to ignore one point of damage for every three points of damage dealt to you. You have advantage on saves against being frightened.

Demon's Blood: While applied, this cherry red warpaint grants you a bonus of +3 to strength. This bonus may exceed your maximum strength score. In addition, enemies have disadvantage when making a save against your Battlecry.

Forest's Heart: While applied, this rich green warpaint grants you an additional +2 to AC. Enemies have advantage on saves against your battlecry, and battlecry may affect up to two enemies. All healing effects on you are increased by an amount equal to your constitution modifier.

Death's Visage: While applied, this black-and-white skull warpaint allows you to force an enemy to reroll their save against your battlecry if you do not like the result. They must take the new roll. In addition, you may cast Unseen Servant once per Long Rest, even while raging. 

Oni's Warpaint: This warpaint grants your face the appearance of an Oni. While applied, you have advantage on intimidation checks and strength saves, and enemies have disadvantage on saves against your battlecry. In additon, whenever you hit an enemy with a melee attack, you may choose to have that attack deal an additional 1d4 thunder damage to all enemies within 5 feet. You may only use this extra damage once per long rest. 

Shield Bash

Beginning at tenth level, you gain access to the Shield Bash attack. As a bonus action, if you are wielding a shield, you may make an attack roll that adds your proficiency bonus and strength modifier. This attack deals 1d12 damage plus your strength modifier, and you shove the creature. If you have the Shield Master feat, you gain advantage with this attack. You may only use Shield Bash once a turn. 

Phalanx

Beginning at 14th level, if you are wielding a shield, you gain access to the Phalanx stance:

As a bonus action on your turn, you assume a defensive posture behind your shield. Whenever an enemy within 5 feet attacks you or an adjacent ally while you have assumed this stance, you may use your reaction to make two attacks against the target: once with your weapon (or fist, if you aren't using a weapon), and again with Shield Bash. During Phalanx Stance, your AC increases by +3. 

While you are in Phalanx Stance, you move at half your base speed. During Phalanx Stance, you may use Shield Bash as a free action on your turn.