Assassin rework playtest 

Assassinate

Starting at 3rd level, you are at your deadliest when you get the drop on your enemies. You can expend a charge to give yourself advantage on on your next attack roll. The attack is considered a critical if you hit. You can use this feature a number of times a day equal to your proficiency modifier. You do not expend a use if the target is considered surprised 

 

Tools of the trade

When you choose this archetype at 3rd level, you gain proficiency with the disguise kit and the poisoner’s kit.

You can spend 10g (worth of alchemical supplies) and an hour to create a basic poison. You can also create one dose as part of a short of long rest.  The basic poison created in this way remains potent for 24 hours, after which it looses it's potency and is lost.

The poison can be applied to a weapon and lasts for 1 hour. The first time the weapon hits, the target must make a DC 12 constitution save or take 1d6 poison damage and is poisoned until the end of their next turn. the DC increases to 15 and the damage increases to 2d6 at level 10. 

 

Tool proficiency

You gain proficiency in alchemist supplies and the disguise kit

Deceptive Charm

You spend 1 minute using your deception and knowledge of people to charm your way into, or out of, any situation. After the minute you must make a deception check against the target's passive insight. If you succeed the target is charmed by you for 1 hour. While charmed in this way, the target considers you an honest and forthcoming individual. This effect ends early if the target takes any damage from one of your allies, if you attack it, if it witnesses you attacking or damaging any of its allies, or if you ask it to do anything that would knowingly negatively effect the individual.

If a target succeeds on its saving throw, the target has no hint that you tried to charm it.

Once you use this feature, you can’t use it again until you finish a short or long rest.

Deadliest of Blades

This feature grants you improved sneak attack, increasing the sneak attack dice increases from a d6 to a d8

Death Strike

Death Strike

Starting at 17th level, you become a master of instant death. When you attack and hit a creature, you can choose to force it to make a Constitution saving throw (DC 8 + your Dexterity modifier + your proficiency bonus). On a failed save, double the damage of your attack against the creature. You can use this feature twice, refreshing on a short or long rest.