Rewinder

A dark path followed only by those willing to sacrifice much, the Rewinder has mastered their chronal flow, able to manipulate and redirect their own timelines to assassinate, infiltrate, or otherwise root out the unjust; a boogeyman, leaping through time.

Chrono Fixation

Starting at 3rd Level when you choose this archetype, your power over the flow of time has begun to manifest. As a Bonus Action, choose a spot within 5ft of you, marking it and catching a glimpse of the future's timeline- your next attack has Advantage. After your next attack, your body returns to your chosen Chronologically Fixed spot, regardless of how far you traveled between choosing a spot and attacking. At 13th Level the range of this ability increases to 30ft. You may use this feature a number of times equal to your Proficiency Bonus per long rest.

Hypersleep

Additionally at 3rd Level, your body has adjusted to the amorphous and ever-shifting slipstream of time. You do not require food, and you require only one hour of sleep a night, though you still require a Long Rest for the purpose of refreshing abilities and avoiding Exhaustion.

Curse of the Ageless

At 9th Level, the chronal flux pervading your being has changed the flow of your natural cycle; you do not naturally show the effects of aging (though you age as normal), and you cannot be aged by magical effects. As an action, you can choose to fluctuate your body to look as old or as young as you wish, height, weight, voice, and any other feature of age following suit; ie, if you choose to look like a child, your height would shrink to that of a child of your race. This feature lasts for one hour, and you have uses of it equal to your Proficiency Bonus per long rest. To an outside observer you are indistinguishable from whatever you choose to appear as, and only True Sight or a similar ability can see through your form.

Time Skip

Starting when you reach 13th Level, a sliver of the timeline has become yours to control, bending spacetime to your will. When you roll initiative, you can instead choose when you go rather than rolling, all other initiative ties lost. Additionally, you can manipulate your own spatial reality to a degree, turning the hands of time forward for yourself. You can expend your movement to instead Teleport to an unoccupied space up to a distance away equal to the movement expended. You can use this feature a number of times equal to your Proficiency Bonus per short or long rest.

Rewind

When you reach 17th Level, your body has become one with Time, your life forfeit to the weave of the universe. You cannot die from natural causes, such as old age, disease, or suffocation. 
Additionally, through the perfection of the control over your own timeline, you have learned to exact chronal assassination against your enemies. Choose up to 5 enemies that you have seen within the last month. They can be any distance from you, though they must be on the same plane of existence as you. As an action, your body warps through time, allowing you to attack each enemy once with Advantage. If your attack hits, you double the amount of Sneak Attack dice used against them. You may use this feature once per 3d4 Long rests.