Stitcher.

Your mastery of theft extends beyond the simple physical and into the temporal. You have a magical knack for spotting and collecting stray moments of time: fragments of potential events that never come to pass. In practice, these collectibles, or "stitches," are almost always harmless to take—after all, any event too important is already cemented in time. Only especially powerful forces, like a deck of many things, have the power to move an event such as that.
Your talent for temporal theft may have been thrust upon you: perhaps you were struck by a strange ripple through time or are trapped in inexplicable time dilation, causing your appearance to hardly age. Repeated trips to and from the realm of the fey could have enlightened you to the nature and slipperiness of time itself. Stranger yet, perhaps you come from a parallel timeline where almost everything was exactly the same as it is now, except for a select few details that only you have noticed. Regardless, you now exist in a reality whose very fabric you can see the stitching of.

Level 3 Feature:

Bonus Proficiencies.

When you choose this archetype at 3rd level, you gain proficiency in the Arcana and History skills if you don't already have it.

Borrow Time.

Also at 3rd level, you can slip through time to attack at supernatural speed. Once on each of your turns when you make a weapon attack, you can choose to draw from the future to hasten the present: the attack roll is then made with advantage. On a hit, the target can't use its bonus action or reaction until the start of your next turn. On a miss, you draw from your own future instead: you can't use your normal bonus action on your next turn.
Hit or miss, you can use a second bonus action until the end of your current turn: this bonus action can't be the same as the first one you used on this turn.
You can use this feature four times, and you regain all expended uses of it whenever you finish a short or long rest.
A creature with the Legendary Resistance trait is more solidly anchored in time. When you use this feature and hit a creature that has this trait, that creature must make a Wisdom saving throw (DC equal to 8 + your proficiency bonus + your Dexterity modifier). On a failed save, it's affected by the feature as normal. On a success, you treat the effect as if you missed with the attack.

Level 9 Feature:

Time Warp.

By 9th level, you can begin to rearrange the sands of time in your favor. When you roll initiative, you can immediately expend a use of your Borrow Time feature to switch your position in the initiative order with another willing creature that you can see within 10 feet of you.
In addition, you can hasten a creature's short rest by letting it partially slip through time. When you and up to five other willing creatures within 5 feet of you begin a short rest, you can cause yourselves to slip through time and arrive at the end of your rest. You and each other creature then fall unconscious for 10 minutes, or 1 minute if you are the only target. At the end of that time, each affected creature snaps back to consciousness and gains the benefit of a short rest. A creature returns to consciousness early, without gaining this benefit, if it takes any damage for the duration. Once you use this feature, you can't do so again until you finish a long rest.

Level 13 Feature:

Quick Thinking.

Starting at 13th level, you can use the bonus action granted by your Cunning Action to make an Intelligence check, make a Wisdom (Perception) check, take the Help action, or take the Use an Object action.
When you make one of these checks as the second bonus action on your turn (after using your Borrow Time feature), you can roll a d6 and add it to the total of the check.

Level 17 Feature:

Time Stop.

By 17th level, you can move through time where others cannot. You can use an action to cast the Time Stop spell, without expending a spell slot. This version of the spell is special: if the spell ends early as a result of you attacking a creature, and you hit with the attack, that creature takes an extra 10d6 psychic damage as the stress of time suddenly resuming shatters its psyche. The attack roll is always made with advantage.
Once you use this feature, you can't do so again until you finish a long rest.