Path of the Mauler

Some barbarians come from tribes where their people believe that true strength can only be measured in contests of unarmed combat.  Their rage courses through every blow and enables them to seize their opponents in crushing embraces with little hope of escape.
    Maulers are typically primitive gladiators that spend the majority of their lives fighting other tribesman to hone their skills.  Exerting their physical prowess over another foe by bashing and bending their bodies until they are broken, these barbarians are some of the scariest warriors on the planet and their abilities border on the supernatural.  There are rumors that these warriors sometimes train by attempting to capture spirits with their bare hands.

Mauling Combat

When you choose this path at 3rd level, you gain the Grappler feat.  Additionally, you gain access to enhanced, close-quarters combat capabilities known as Mauler Damage: 

• You can roll a 1d6 for unarmed strike damage. At 11th level, this damage changes to 1d8.  At 17th level, this damage changes to 1d10.
• While raging, you deal your Mauler Damage automatically if you succeed on grappling your foe.
• While raging, you can add your Rage Damage bonus to your grapple checks.

Supernatural Torque

Starting at 6th level, your unarmed strikes count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.
    While raging, your ability to sling creatures around greatly improves.  You cannot be restrained and can make attacks against a pinned foe.  Additionally, you can move creatures around at full speed and your carrying capacity is doubled.

Reaping Wrestler

Beginning at 10th level, you can powerfully slam creatures within your grasp.  Whenever you are raging and successfully pin a creature, they automatically take damage equal to your Mauler Damage.  You can then choose to knock yourself and your grappled foe prone. 
    Additionally, you gain access to specific holds that are designed to debilitate foes when they are pinned:

• Leg Lock. As an action, you can attempt to isolate a leg and twist it to cripple your foe’s ability to move.  The pinned creature must make a Constitution saving throw (DC = 8 + your proficiency bonus + your Strength modifier).  On a failed save, they take damage equal to your 2 x your Mauler Damage and have their movement speed reduced by half for 1 minute.  If they fail the save by 5 or more, you severely strain the leg and their speed is reduced to 0 instead for the duration.  If they fail by 10 or more, then their leg is broken and the effect lasts until they are healed or experience a long rest.  On a successful save, they only take half damage and suffer no effects.
• Arm Bar. As an action, you can attempt to snag an arm and bend it to hamper your foe’s ability to hold objects.  The pinned creature must make a Constitution saving throw (DC = 8 + your proficiency bonus + your Strength modifier).  On a failed save, they take damage equal to your 2 x your Mauler Damage and they drop whatever object they are holding.  If they fail the save by 5 or more, you severely strain the arm and they cannot hold anything for 1 minute.  If they fail by 10 or more, then their arm is broken and the effect lasts until they are healed or experience a long rest. On a successful save, they only take half damage and suffer no effects.
• Choke Hold. As an action, you can attempt to take their neck and squeeze it until your foe begins to lose consciousness.  The pinned creature must make a Constitution saving throw (DC = 8 + your proficiency bonus + your Strength modifier).  On a failed save, they take damage equal to your 2 x your Mauler Damage and they are stunned for until the end of their next turn.  If they fail by 10 or more, then they fall unconscious for 1 minute and are treated as though they are suffocating.   If they remain pinned this way, they survive for a number of rounds equal to their Constitution modifier.  At the start of their next turn, the creature drops to 0 hit points and is dying.  On a successful save, they only take half damage and suffer no effect.

    If you try to utilize the same technique against a creature that has already failed their saving throw, then they make the next saving throw attempt with disadvantage.  However, these techniques do not work on creatures with no discernible anatomy.  This includes oozes, plants, ghosts, wraiths, and other similar creatures.  Undead are immune to the effects of choke hold.

Clutch the Unclutchable

Beginning at 14th level, creatures that have the ability to become incorporeal or shift themselves to the ethereal plane (such as with the etherealness spell) do not automatically succeed on a check to escape your grapple.  They must succeed on a Acrobatics or Athletics check or they are still grappled by you.
    Additionally, creatures with abilities or spells that enable them to teleport must succeed on a Acrobatics or Athletics check or suffer consequences.  If they fail the ability check and the teleportation only affects the caster, then the teleportation automatically fails.  If they fail the ability check and the teleportation includes willing creatures, you can choose to have the spell fail or travel along with the caster to their destination.