The Temple of Time discovered that there is a river like flow of time. These monks have then been taught to connect their Ki to alter the flow to fast it forward, Rewind it or even stop it completly.

Rewind

Reverse the flow of time to alter fate. 

-Rewind time by spending 1 Ki points to reroll ability checks and saving throws (Can only be used once per turn, will be upgraded to twice at 11th lvl and thrice at lvl 17)
no action required

Look into the future

You use your Ki to get a sneak peek of your next attacker and what they will do. You then force disadvantage on that attack

Costs 2 ki points

Used as your bonus action and only works on one target at a time (increases to 2 targets at lvl 11 and 3 targets at lvl 17)

Time Stop

Through the power of Ki you stop time for a brief moment. You can cast the time stop spell 

Slow motion

You have learnt to manipulate the flow of time around a certain point

You learn the Slow spell for the cost of 4 Ki points

DC=Ki DC