Brawler (untested)

Tough

At 3lv., your hit point maximum increases by 1 for every level in this class and increases by 1 again whenever you gain a level in this class. You get +1 to AC and you get additional +1 at level 10. Also you can use DEX instead of STR when shoving, grappling or maintaining a grapple.

Stance

At 3lv. when you are in combat you take one of your stances. Once per your turn you can switch your stance without using any action after that it cost Bonus Action.

Offensive stance: Your melee attacks deal +1 damage (+2 at 14Lv.) At 14Lv. you can also use opportunity attack when target move into range or move within your range.

Defensive stance: You get +1 to AC (+2 at 14LV.) At 14Lv. damage you take from attacks is reduce by your Martial Arts dice and by 1 for every dice used in damage roll.

Brawlers experience

From 3Lv. you get following maneuvers:

Grappler: You can try to grapple or escape a grapple as bonus action.

Throat chop: Once per turn when you hit a creature with melee attack you can prevent it from speaking until start of your next turn.

Ribs shattering strike: Once per tur when you hit a creature with melee attack you can create a weak spot that make all attacks deal +1 damage. From 6Lv. attacks ageinst that creature are critical at roll 19-20. This effect ends when target regain any amount of hit points (min 1) or somebody use action to do Medicin check against your Ki save DC.

Flesh ripper: Once per tur when you hit a creature with melee attack you can create bleeding wound. At start of its turn target take damage equal to your Martial dice for every round this effect was active. For example in first round you roll 1 dice in second 2 dices. From 6Lv. Damage starst witch 2 dices insted of one (you still increase damage as normal). This effect ends when target regain any amount of hit points (min 1) or somebody use action to do Medicin check against your Ki save DC. Counstracts and Undeads are immune to this effect.

 K.O.

From  6Lv. when you make crittical hit you can force target to make CON save against your Ki save DC or fall unconscious for 1d4 rounds.

Brawl

From 6Lv. when you make a melee attack you can use same attack roll to make unarmed strike against other target in your raech on hit you deal damage equal to one roll of your Martial dice.

Grapler

You have advantage on attack rolls against targe you are grapling and target that you are graplin have disadvantage on attacks rolls. You can also bind one of your limbs with one limb of target you are grappling both limbs can't be used. You can end this at any moment.

Iron Fist

From 10Lv you can ignore eny effect that would turn your critical hits into normal hits.

Brutal Critical

Beginning at 11th level, you can roll one additional weapon damage die when determining the extra damage for a critical hit with a melee attack.

Improved Critical

Beginning  at 11th level your weapon attacks score a critical hit on a roll of 19 or 20. 18-20 if target is under effect of Ribs shattering strike.

God's Fist

From level 17th once per turn when you make a melee attack but beafore you make attack roll you can make this attack deal extra 50 poinst of damage.

Last Stand

From level 17th once per long rest when you drop to 0 hit points before you fall unconscious you can regein halve of your hit poinst.