The Grave Robber

There is no honor among thieves, and fewer among those that plunder the dead, once of noble blood, The Grave Robber now stalks the night like a phantom. Their former life buried beneath the dir they disturb, They do not stand and fight--- They unravel their enemies, setting their enemies off balance through ailments and afflictions, Every faltering step, every slowed reaction is another opening for them to exploit, dragging them ever closer to the grave

Level 3: Night Moves

Night Owl: You only require 4 hours of rest to get the benefits of a long rest

Scout: You have Advantage on Wisdom(Perception) and Intelligence(Investigation) Checks made at Night

Pilfer: At the end of a long rest, you can find a mundane item worth no more than 1 GP, that could reasonably be found in your surroundings, The DM has the final say but its encouraged to be lenient

Level 3: Gallous Tricks

You gain an additional way to use your Sneak Attack. You don't need advantage on the attack roll to use your sneak attack against a creature if it afflicted with a condition, and yo don't have disadvantage on the attack roll. all the other rules for sneak attack still apply too you. 

Additionally, whenever you hit a creature that is affected by a condition and use sneak attack, that creature gains a stacking -1 penalty to saving throws and ability checks made to avoid or end that condition, if the creature has multiple conditions than you get you choose which condtion the penalty applies too. The penalty applies until the condition is removed, and it can not exceed your Dexterity Modifier.

Level 9: Snuff Box

As a bonus action, choose one willing creature within 5 feet and one of the following conditions, Blinded, Charmed, Deafened, Frightened, Paralyzed, Stunned, or Poisoned. That creature has Advantage on all saving throws and ability checks to avoid or end that condition on itself for the next minute, Additionally if that creature is affected by that chosen condition, it immediately ends on it. 

Level 13: Deadly Aim

After you use Steady Aim, The Sneak Attack damage cost of the next Cunning Strike Option you use this turn is reduced by two dice (minimum of 0) Starting at 14th level you can either reduce the cost of cunning strikes or devious strikes this way. 

Level 17: Smoke and Mirror

When you make a ability check or saving throw to avoid or end a condition of yourself, You can use Dexterity instead of the usual ability

Additionally whenever a creature within 30 feet of you would be affected by the Blinded, Frightened or Poisoned condition you can change the condition to one of the other two instead, if the creature is willing(no action required) Otherwise The creature must succeed on a Wisdom Saving Throw ( DC= 8+Proficiency Bonus+ Dexterity Modifier) or have the condition changed