The Fonz

Even as a monk you did not have enough time to properly learn a style of combat, and have instead taken to a more thuggish brawling style.

Seeing Red

Upon seeing your own blood over your eyes, you are enraged and may take one more attack, move 5 more feet, or use one bonus action.
Lasts an equal amount of time as your proficiency modifier, and can be used once per short or long rest.
(Ex: +3 Proficiency is 3 turns)
Granted at 3rd level.

Savagery

Gain proficiency with improvised weapons, and lose any proficiency with martial weaponry. Granted at 3rd level.

Frenzied Counter

After reaching half health may take a reaction to instantly hit back. Gained at 6th level.

Dirty Offense

The Brawler may use an improvised weapon as a free action, but rolls with disadvantage and breaks the weapon in the process, regardless of if the attack hits. Granted at 11th level.

Focused Rage

Whilst Seeing Red is active, no movement penalties can be applied. Granted at 17th level.