Some monks reasoned that they would be unbeatable if  they could not be hit. And the only way to not be able to be hit would be through speed. Some monks who took this path could travel so fast they became invisible.

Flashstep

Your speed is increased by 20 and your dexterity score is increased by 2

Blink speed

At 6th level, you have attained incredible speed and now can cast the spell blink once per long rest. At higher levels: at level 17 you gain enough speed to be able to cast blink infinitely.

Incredible reflexes

When an enemy attacks you, you can impose disadvantage on that attck roll.

Flashstep strike

Using your incredible speed, you can strike an enemy at massive velocity, they must make a constitution saving throw DC your monk level +5. On a success, they take 10d10 bludgeoning damage. On a failiure they take 10d100 bludgeoning damage. This attack ignores resistance and immunity to bludgeoning damage.