Not all the members of a thieves' guild are slender spies that skulk through the darkness.  Others are the enforcers at the doors, the first line of defense to any establishment.  Just because their methods are different, the result tend to be the same; Quick and painful death to their enemies.  Brutish enforcers will use heavy clubs, massive hammers, and their own fists to inflict terrible damage no matter where they are on the battlefield.

Bonus Proficiencies

When you choose this archetype at 3rd level, you gain proficiency with medium armor and martial weapons.

Overwhelming Brutality

Starting at 3rd level, you can use your brute strength to overwhelm an attacker.  You can roll a d8 in place of the normal damage of your unarmed strike provided you are not wielding a shield or other weapon.  Otherwise, this damage die is reduced to a d6.  Additionally, you can apply your Sneak Attack damage using an unarmed strike or with any melee weapon attack that uses Strength, provided that weapon does not have the special or reach property.

Colossal Hit

At 9th level when you hit creature with a melee weapon, you can attempt to shove the creature as a bonus action. If you succeed, you can push the creature up to 15 feet away from you, rather than 5 feet, and if you choose to shove the target prone you can make an unarmed strike against the target as part of the same bonus action.

Menacing Threat

Beginning at 13th level, your sheer presence and force of will is enough to make most crumble. As a bonus action, choose one creature that you can see within 5 feet of you. If the creature can see or hear you, it must succeed on a Wisdom saving throw (DC equal to 8 + proficiency bonus + your Strength modifier) or be frightened of you until the end of the creature's next turn.

While a creature is frightened of you, your attack rolls against them are made with advantage.

Blood Frenzy

Starting at 17th level, you have advantage on attack rolls if you are missing at least half of your hit points.