Weapon Expert

A warrior stands on a bridge between a defenseless town and a evil warband of goblins, as the ugly savages charge he grips his trusty longsword the only weapon he carries. Like lightning he begins to slash goblins in half as though he was a god of war. Afterwards the villagers gather around as their "hero" cleans his precious blade.

A half elf readies her bow, seeing the ogres throwing her unconscious friends into a wooden bow. so as they argue who they eat first. As she pulls the string back the environment around her almost seems to bend and twist giving her the perfect shot into the ear of all three of the dim-witted brutes. The single arrow shreds through not only the ogres but also the latch holding the box shut.

The hobgoblins all begin to mock the simpleton goliath who has walked into there camp. But this goliath came seeking vengeance for the innocent people they slaughtered. As the red goblinoids continue to laugh and begin to surround him brandishing swords and axes those laughs turn to silent expressions of fear as the giant glaive slices the three closest hobgoblins in half. Now he laughs as tells his enemies retribution has come.

While many fighters can wield almost any weapon The Weapon Masters pride themselves for creating various fighting styles based off one weapon they spend there whole lives studying.

Vessel of Combat

Upon choosing this subclass you pick one weapon you are proficient and that becomes your Vessel of Combat. While you can wield other weapons any weapon that is your weapon of study gets +1 to attack and damage rolls. 

Weapon of Choice

You have trained not only in the conventional use of your weapon but also have created your own style of combat with it. Your weapon gains an additional weapon property that only works when your character wields there specific weapon.

Weapon Properties:

Versatility- Your weapon can be wielded with one or two hands. If your weapon was only two handed before the one handed damage die is one die less than the two handed and vice versa for a one handed weapon. (ie Versatile great sword dealing 2d4 damage one handed)

Thrown- Your weapon is now throwable. Versatile weapons can be thrown one or two handed the range of this weapon is 30/90 feet 

Finesse- Your weapon can be wielded with STR or DEX.

Reach- Your weapon's reach is extended by 5 feet. (Can be chosen multiple times)

Great- Your weapon becomes heavy and requires two hands two wield it and the damage becomes double what it originally was. (ie 1d8 morning star becomes a 2d8 great morning star)

 Silvered Steel- Your weapon ignores nonmagical immunities and resistances. 

Fighter's Focus

Upon reaching level 7 you can channel all your training and focus to become a near unstoppable warrior. Once per day you can add your INT mod to all intuitive, attack, and damage rolls (min of 1) you also add that bonus on any ability check that you are proficient in. This state last for 10 minutes but you must be carrying your special weapon and the combat bonuses apply only if you attack with that weapon.

Prized Possesion

At level 10 your weapon can also assist you out of battle, any ability check that you can use your weapon to assist you on gains a bonus equal to 1d4+ your INT modifier (min of 1). 

(ie using your weapon to Intimidate someone or showing off your weapon and skills as a performance check)

My Weapon is my Strength

You can gain "expertise" in your Vessel of War, when making an attack you can choose to double your proficiency before the DM announces when an attack fails or succeeds. If the attack hits after gaining "expertise" you can add your proficiency bonus to the damage roll. You can do this an amount per long rest equal to your INT modifier. 

Elite Focus

You can use Fighter's Focus three times per long rest.