Bruiser

When in combat, Bruisers doesn't concern themselves with honor or rules. They use their fists, legs and even surrounding objects to gain any advantage over their opponents. While some Bruisers may be foot soldiers used to fighting for survival, most are street thugs, criminals and commoners, honing their skills in back alleys and taverns. 

Unarmed Expert

Beginning when you choose this archetype at 3rd level, you are proficient with unarmed combat and improvised weapons. You can roll a d4 in place of the normal damage of your unarmed strike. 

Unarmed strike dice increases to D6 at 7th level.

Sucker Punch

Starting at 3rd level, if you have free hand, after using Attack action, you are able to do additional unarmed strike as a bonus action. This strike can be delivered between multiple attacks from single Attack action. 

Additionally, once per turn, after hitting an opponent with an unarmed strike you can choose to do one of the following Sucker Punch option.
Some of those options require a saving throw from your target, In that case it's equal to 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice).

Push/Pull. You move your oponent and yourself 5 feet in chosen direction. This movement doesn't provoke attacks of opportunity. 

Trip. Your opponent must make a Strength saving throw against your save DC or be knocked prone. 

Grapple. Your opponent must make Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses the ability to use) against your save DC. On a failed check they become  grappled. 

Shove. You push the target 5 + your proficiency bonus + your Strength bonus feet away from you. 

Distract. You distract the target, giving advantage on next attack against them. 

You can improve your unamred strike a number of times equal to twice your proficiency bonus, and you regain all expended uses when you finish a short or long rest.

Brutal Improvisation

Starting at 7th level, any improvised weapons you use gain thrown property and deals 1d6 damage of appropriate damage type and can be used for Sucker Punch feature same way as an unarmed strike strike. 

Additionally, when you make a successful attack with an improvised weapon you can choose to break the weapon on your enemy, dealing 2d6 damage and applying one of Sucker Punch feature's effects. This is not counted toward usual per turn or per rest limits.

Amount of damage dealt when breaking improvised weapon increases by 1d6 at 10th level(3d6) and then again at 15th level(4d6). 

Brawl-ready

You are always aware of your environment and ready to fight. You cannot be Surprised, you can add your proficiency modifier to Initiaitve rolls and when you roll initiative and have a free hand you can grab an improvised weapon from your surroundings as a free action. If there is nothing to use as an improvised weapon, you can use your bonuse action to pull something unexpected from your belongings to use as an weapon.  
In addition, you gain advantage on Wisdom (Insight) checks when determining intentions toward you and your companions. 

Wide swings

Starting at 15th level, whenever you make an unarmed or improvised weapon attack you can also target one another creature within 5 feet of you. You make separate attack and damage rolls for both creatures. 

Interplanar bruiser

Thanks to your exprience, you are prepared to deal with unnatural on the fly. At 18th level, your unarmed strikes are considered magical and when you grab improvised weapon you can choose what type of damage it will do. Whenever you use bonuse action to do unarmed of improvised weapon attack, you can do so twice.