Unarmed fighters are not unlike monks although they chose not to study in the arts of Ki and decided to try to hone their physical body more. This way of fighting is very unique and not many people possess knowledge of the art style, often meaning that fighters of this style dont get the recognition they deserve. Often people of this style end up using weaponry until they have to resort to their skills with their fists.

Bonus Fighting Style

When you choose this subclass at 3rd level, you gain the unarmed fighter fighting style if not previously selected. Your unarmed strikes count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Style Description:

Your unarmed strikes can deal bludgeoning damage equal to 1d6 + your Strength modifier on a hit. If you aren’t wielding any weapons or a shield when you make the attack roll, the d6 becomes a d8.

At the start of each of your turns, you can deal 1d4 bludgeoning damage to one creature grappled by you.

 

You also gain proficiency in Athletics and Acrobatics and Dexterity saving throws.

Unarmored Defense

At 3th level, While you are not wearing any armor, your Armor Class equals 10 + your Strength modifier + your Constitution modifier. You can use a shield and still gain this benefit.

Resilience of Champions

At 7th level, you have grown resilient to combat. You develop resistance to all non-magical Bludgeoning, Slashing and Piercing damage.

Flanking Master

At 10th level, you are immune to flanking. You also have advantage on initiative rolls. In addition, you you can’t be surprised, except when incapacitated by something other than nonmagical sleep. You will awaken if you are sleeping naturally when combat begins.

It Ain't Over 'till the Bell Rings

Starting at 15th level, When you are reduced to 0 HP but not killed, you can drop to one HP instead once per long rest. Once activated you can expend a use of your action surge to interrupt your opponent's turn to take the attack action. 

Undying Spirit

At 18th level, at the start of each of your turns, you regain hit points equal to half your fighter level (rounded down) if you have no more than half your max hit points. You don't gain this benefit if you have 0 hit points.