Using your inner Ki and the enemies movements against them you can sway the tide of battle in your favor. The battle around you is the music you need dance through the fight and come out the victor. 

Choreography

• Elegant Step. You gain proficiency in the Performance skill if you don't already have it.
• Graceful Step. When you use your Step of the Wind to Dash or Disengage, you gain a bonus to your AC equal to your Wisdom modifier (minimum of +1) until the beginning of your next turn.
• Shifting Step. If a creature no more than two sizes larger than you moves at least 10 feet before making a melee attack against you, you can expend 1 Ki point and use your reaction to send the creature 10 feet in a direction of your choice. This creature must succeed on a Dexterity saving throw (8 + your Dex bonus + proficiency bonus) or be knocked prone
• Steady Step. You have advantage on Dexterity and Strength saving throws to maintain your footing or resist being knocked prone.

Lets Dance

At 6th level, You learn to take control of the Ki within enemies to force them into the choreography of your deadly dance. Whenever you hit a creature with one of the attacks granted by your Flurry of Blows, you may expend 1 Ki point to force the creature to make a Wisdom saving throw against your Ki save DC. If the target creature is more than one size larger than you, it succeeds automatically.

On a  failed save, the creature is charmed by you for 1 minute. While charmed this way, the creature is grappled by you and cannot use it's action to escape the grapple. As long as this effect lasts, you can use your reaction to cause any attack or magical effect targeting you to instead target the charmed creature. The creature can repeat the saving throw at the start of each of it's turns, ending the effect on a success. The effect also ends if you stop grappling the creature

Inspiring Flourish

At 11th level, you can inspire others through the beautiful movements of your body. You can use a bonus action to choose one creature other than yourself within 30 feet of you that can see you. Once within the next 10 minutes, that creature gains a bonus to an attack roll, ability check, or saving throw of their choice equal to one roll of your Martial Arts die. The creature can wait until after it rolls the d20 before deciding to use the Martial Arts die, but must decide before the DM says whether the roll succeeds or fails. You can use this feature a number of times equal to your Charisma modifier (minimum of 1), with uses resetting after a long rest.

Endless Dance

At 17th level, you have learned to steal the Ki of your enemies through dance. Each time a creature fails it's saving throw against your Let's Dance feature, you regain 2 expent Ki points

You also have the option to expend 2 Ki points to raise the save DC against Let's Dance and the DC will remain higher through that grapple.