This subclass eschues mystical studies for the way of SPEEED, BABYYY. Get faster, do more stuff, confuse your enemies, become unstoppable. Just a dumb little homebrew I came up with for a specific character.

Beating Gale

Your hands move so quickly that you can fit in attacks in the middle of other moves. For an additional ki point, you may make an additional attack as part of flurry of blows, patient defense, and step of the wind.

Fast Hands

You gain proficiency with Sleight of Hand if you don't already have it.

Swirling Storm

Your study of speed makes your attacks unpredictable and confusing. you may spend 3 ki points to make a feinting attack: you gain advantage on this attack and any others you make this turn. In addition, you may use patient defense as a reaction.

Windwall

Your body moves so quickly that attacks seem to pass through you.

As a bonus action, spend ki to gain resistances until your next turn:
2 ki--bludgeoning, piercing, and slashing damage
3 ki--fire, cold, acid, poison damage
4 ki--radiant, necrotic, lightning, thunder damage
5 ki--force, psychic damage

Unstoppable Force

You are so quick and graceful that it becomes difficult even to slow you down. As an action, spend 5 ki and gain an additional 10 feet of movement, become unaffected by difficult terrain, and gain advantage on grapple checks and on saves against spells that would slow, paralyze, or restrain you for the next minute. If you use Step of the Wind while under the effects of this feature, you may triple your jump distance.