All monks are swift, but Harriers take it to a new level. Twisting and dashing around the battlefield, their unbelievable speed lets them hit hard and disappear. Harriers excel in hit and run attacks, rarely letting their opponents answer their swift barrages. Once a harrier begins pursuit of a target, rare is the one who escapes them. Harriers frequently use light weapons such as a dagger or small hammers, since opponents often underestimate how deadly a tool it can be for one who is so blindingly fast. 

 

Harrying Speed

Starting at level 3, you have trained your muscles into precise instruments of explosive speed.

-Whenever you use at least 10 feet of move speed before you take the attack action, you may make an additional attack against a different target as part of the same attack action. This target does not have to be adjacent to the original one provided you have sufficient move speed to reach the new target.

- Your move speed increases by 10 feet

- Whenever you take the dash or disengage action, your AC increases by 2 until your next turn.

- When using a weapon with the light property, Harriers get +1 to attack and damage. All light weapons count as monk weapons for you.

Harrier's Charge

At level 6, you can use your immense speed to transfer your momentum into a devastating attack. If you take the dash action on your turn and end it adjacent to an enemy, you may make a single attack against them with advantage. If you hit, you deal additional force damage on this strike equal to your dexterity bonus. This is damage is multiplied on a critical hit. You may instead spend a Ki point to turn this into a flurry of blows, with each strike dealing the additional force damage, but doing so leaves you vulnerable to a counter strike. All attacks made on you have advantage until the beginning of your next turn.

In addition any light weapons you are wielding count as magical for bypassing damage resistance.

Swift Counter

At level 11 you have sharpened your reflexes so much you can now turn attacks from enemies to your advantage. If you provoke an attack of opportunity from movement and the attack misses, you may then make a single counter attack against that target with disadvantage. You may do this a number of times per round equal to your proficiency bonus. You may instead choose to spend a ki point to negate the disadvantage.  Any uses of this ability count as your reaction for this round.

Dance of 1000 Blows

At level 17 you become a blinding whirlwind of speed. You may spend 3 ki points to move with superhuman speed, allowing you to make a single attack against every target within 15 feet of you, provided they are not behind cover or in difficult terrain. You must be able to see your targets. You may not use a bonus action this turn if you choose to make this attack.

Your move speed increase by 10 feet.