Shadow Stalker

Beginning at 3rd level, when the rogue chooses this archetype, the rogue's shadow merges with him/her and is no longer cast onto objects or the ground. Instead, the stuff of shadow coalesces within the rogue and seeps from the rogue's flesh like whisps of black flame. The rogue also gains Devil's Sight up to 120ft.

Shadow Body

At 3rd level, the rogue can gather the shadows around and within him/her to become incorporeal. In this form, the shadow stalker can't be harmed by conventional means; force and radiant damage can still cause harm. Also in this form, the shadow stalker can slip through doorways and windows just as a shadow would. Shadow Body adds a +2 to stealth checks and lasts until the end of his/her next turn. It scales to +3 at 6th level, +4 at 11th level, and +5 at 17th. This can be done twice per day per short/long rest.

Shadow Step

At 3rd level, the shadow stalker gains the ability to step from one shadow to another. When he/she is in dim light or darkness, as a bonus action, the shadow stalker can teleport up to 60ft to an unoccupied space he/she can see that is also in dim light or darkness. He/she then has advantage on the first melee attack he/she makes before the end of the turn.

Shadow Blade

At 9th level, the shadow stalker gains the ability to weave a blade from the stuff of shadow. The shadow blade remains for 1d4 rounds, but can be dismissed early by the shadow stalker. It does 6d6 +3 necrotic damage, and inflicts a 1d4 bleed affect that lasts until the end your next turn.

Fatal Teleport

At 17th level, the shadow stalker can teleport behind a weakened enemy and land a fatal blow. When an enemy has been severely injured in combat, the shadow stalker senses it losing it's grip on life, and can teleport to a maximum of 60ft to that enemey to deliver a melee attack from behind. Upon landing that attack, the enemy must make a constitution save against a DC8(+Proficiency Bonus +Dexterity Mod) or die. On a successful save, the enemy still takes 10d10 necrotic damage. This can only be used once per day per short/long rest.

Shadow Twin

At 13th level, the shadow stalker gains the ability to create a life-like replica of him/herself. As a bonus action, the shadow stalker can manifest a tangible twin of him/herself from the stuff of shadow. It can be placed in any unoccupied space within 30ft of the shadow stalker. The Shadow Twin has an AC of DC8+1/2 shadow stalker level; it caps at 18. For the Shadow Twin, HP is always half that of the shadow stalker. The Shadow Twin disappears when all of its hit points have been depleted, is dismissed by the shadow stalker, or the shadow stalker moves to a distance greater than 30ft.