Inkwalker (1)

There are many similarities between rogues of all types, whether that be hiding, flanking, or running. This subclass of Rogue focuses on hiding and tormenting your enemies with the ink that surrounds you from an alternate nightmare realm. 

Nightmare Realm 
Inkwalker Rogues are creatures of nearly any race that have been trapped in, sucked into, or have become a part of an alternate realm called the Nightmare Realm. Here, upon exiting, however that may have come to pass, they've been left with a marking somewhere on their body depicting their screaming face surrounded by a dark-colored aura. This is where their inky abilities emanate from. While an Inkwalker Rogue is in the Nightmare Realm, their ink-related abilities are heightened to almost God-like extension, allowing them to literally create or destroy any matter they can see by thinking about it. 

Spellcasting 
Rogues cast magics from the very culmination of their being, their soul. Thus, their spellcasting ability is Constitution. They have access to several utility-level Spells from 3rd level. 

Abyssal Spellcasting

At 3rd level, you gain knowledge of the Nightmare Realm, which alone grants extraordinary power. 

You know the following Spells: Misty Step , False Life , Shield , Minor Illusion , Detect Magic , Eldritch Blast , and Chill Touch. They can each be cast a number of times per Short Rest equal to your Constitution Modifier. 

You also now have Blindsight with a range of 20 ft. 

Mistweaver

At 9th level, the very fiber of your being warns you of danger, allowing you to do realm-bending, impossible acts of dark magic, often against your will. 

Once per Long Rest, when you are lowered below 1 Hit Point and are not killed, you instead lower to 1 Hit Point and Mistweaver activates. 
Upon activation, your attacker will be transported into the Nightmare Realm until the start of your next turn and they 1d20 Necrotic damage. If this kills them, you are healed for the damage result. Until the end of your next turn, you have an extra Action, Bonus Action, and Reaction. All melee and ranged damage you deal now deals the Necrotic type. For the duration, you also have Advantage on Saving Throws and Ability Checks. 

You gain the innate ability to weave darkness into the energy around you. 
When a creature within 15 ft of you, including yourself, deals non-magic melee or ranged damage, you can spend a Reaction to convert its damage type into Necrotic damage. It will also immediately deal 1d4 extra damage. 

Shadow Puppet

At 13th level, you have a way with shadows, darkness, and mists others do not. 

When in a fog, mist, or darkness, difficult terrain has no affect on you and your movement speed increases by 10 ft. 
Along with this, while in a fog, mist, or darkness, you gain Advantage with Dexterity (Stealth) Checks, Wisdom (Perception) checks, and a new Bonus Action called Mistsense, which allows you to sense the exact location of a creature within a group of darkness, fog, or mist that you are also in. 

To help with this, once per Long Rest, you can cast the spell Darkness. You can cast it a number of times equal to 2 + your Constitution Modifier. 

Void Portals

At 17th level, once you get used to and better understand your dark vortex gifts, you may begin to manipulate them at will. 

As an Action, you can use Begone. This allows you to instantly summon a portal on a surface, like a ceiling, wall, or floor, that sucks in a single target creature. They can be stored until the end of your next turn, before being spit out within 5 ft of you in an empty space. 

As a Bonus Action, you can use Release. This allows you to spit out a creature you have recently sucked into a portal into the Nightmare Realm. You summon a portal on a surface and the creature you spit out is thrown like a projectile in any direction the portal is facing when summoned. It is thrown a distance equal to 10 ft + an extra 5 ft for every 1 point in your Constitution Modifier and if the thrown creature collides with another creature, they both take 1d10 Necrotic damage and both fall prone. 

As a Reaction, you can use Decay. This allows you to suck yourself into a portal, entering the Nightmare Realm until the start of your next turn, where you are spit out from a portal up to 30 ft from your original position. You can use this to dodge a non-magic, non-critical success melee or ranged attack targeting you. You can use this feature twice per Short Rest.