Shadow infiltrator

A being from the Shadowfell has taken an interest in you whether it being from a frequent proximity to death or perhaps the fact that you been brought to the brink yourself. You don't know. This being has chosen you as it's champion on the materiale plane, maybe to ferry souls to the other side or maybe bring the being over to the material plane. Whether it is the Raven queen herself or a lesser creature from the Shadowfell. You have been granted powers closely linked to the shadows making you skilling in subterfuge and deception, making you the ideal assassin, spy, or even the cruellest occupation of them all a tax-collecter. 

Liquid Shadow

Starting at 3rd level, you are granted liquid shadow from a realm unknown to you. 

As an action you can throw a bottle of liquid shadow up to 60 ft the bottle smashes on impact releasing magical darkness in 10 foot circle, which disperses after ten rounds or if the Daylight spell is cast within the darkness.

Alternatively you can use you reaction when targeted with an attack roll to drop the flask shrouding yourself in darkness, the triggering attack is made at disadvantage. You make this decision after you see whether the attack roll succeeds or fails. The target must use the result of the second roll.

You have an amount of bottles with liquid shadow equal to your proficiency bonus  and on a long rest the bottles reappear in your possession. 

The Right Training for the Job

When you choose this archetype at 3rd level, you gain expertise and advantage in the Deception skill and proficiency with the forgery kit and disguise kit. 

Moving in the Shadows

At 9th level, you gain the ability to step from one shadow into another. When you are in dim light or darkness, as a bonus action you can teleport up to 60 feet to an unoccupied space you can see that is also in dim light or darkness. You then have advantage on the first melee attack you make before the end of the turn.

Shadow Disguise

At 13th level, you gain the ability to adopt a humanoid’s persona. When a humanoid dies within 30 feet of you, you can magically capture its shadow using your reaction. You retain this shadow until you use it or you finish a long rest.

You can use the shadow as an action. When you do so, it vanishes, magically transforming into a disguise that appears on you. You now look like the dead person, but healthy and alive. This disguise lasts for 1 hour or until you end it as a bonus action.

While you’re in the disguise, you gain access to all information that the humanoid would freely share with a casual acquaintance. Such information includes general details on its background and personal life, but doesn’t include secrets. The information is enough that you can pass yourself off as the person by drawing on its memories.

Another creature can see through this disguise by succeeding on a Wisdom (Insight) check contested by your Charisma (Deception) check. You gain a +5 bonus to your check.

Once you capture a shadow with this feature, you can’t capture another one with it until you finish a short or long rest.

Shadows Guide

Starting at 17th level, the shadows guide you to strike true if you would have otherwise failed. If you miss with an attack roll, you can roll it again with advantage. Once you do so, you can’t use this feature again until you finish a short or long rest.