Ki

A fighter who studies the ways of the monk and tries to add his own spin to it.

Inner strength

You harnest the power to use ki like a monk. Starting at 3rd level when you gain this feature you gain 3 points of ki. If you also have levels of monk these points stack for determining how many you have. 

You also gain a new action in combat called weapon flurry. When using a one handed monk weapon in each hand you can spend 1 ki point as a bonus action to attack twice with your off hand weapon. 

You don't add your ability modifier to the damage rolls for this action unless you have the two weapon fighting fighting style.

Martial arts

Starting at 3rd level, whenever you hit with an unarmed strike or monk weapon that you’re proficient with and deal damage, you can change the damage die based on your fighter level:
as shown on the Martial Arts Damage table.

This stacks with levels of the Monk class.

Martial Arts Damage

Fighter Level	Damage
3rd	1d4
5th	1d6
11th	1d8
17th	1d10

Quick

 You move faster than normal even in armor. Your walking speed increases by 10ft

As part of your move action you can increase your walking speed by 5ft for every ki point spent. This effect lasts until the end of your turn. You can't spend more than 5 ki points at once with this feature

Additional Fighting Style

At 10th level, you can choose a second option from the Fighting Style feature.

Archery

You gain a +2 bonus to attack rolls you make with ranged weapons.

Defense

While you are wearing armor, you gain a +1 bonus to AC.

Dueling

When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.

Great Weapon Fighting

When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.

Protection

When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.

Two-Weapon Fighting

When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.

Wise Combat

Starting at 15th level, you learn how to gain the benefit of using a shield while using a monk weapon in each hand.

You also learn how to increase your defense further by using ki points. You can use up to 5 ki points as a reaction to increase your armor class by an equal amount.

Perfect self

At 18th level, when you roll for initiative and have no ki points remaining, you regain 4 ki points.