Straddling the line between living and dead those on the Path of Assimilation truly do become one with the spirit world. The living or perhaps not so much at times embodiment of death these wraith-like beings possess powers from beyond the grave.

Wraith Assimilation

As part of you becomes consumed by wraith energies, as your body decays and becomes more spiritual you also gain unique traits and abilities based on what part of your body is consumed. You gain one of the following features.

Legs: You gain a fly speed equal to your walking speed. 

Arms: You can channel 1d4 extra cold damage to all unarmed and melee attacks so long as you are holding the weapon without throwing it.

Heart: Gain advantage against being charmed or frightened as the machinations of the living no longer concern or interest you. You are unable to feel emotions unless provoked to the extreme.

Face: Your eyes and throat melt away to reveal a ghostly visage underneath, gain advantage to all intimidation checks as you can now freely manipulate your voice and face to taunt/seduce/torment your enemies.  You gain dark vision up to 60 ft and can see into the realm of the dead. 

Cadaver: as your lungs and stomach are consumed you are resistant to poison damage. You no longer need to breathe or eat and drink.

Continual Assimilation

You may pick an additional Wraith assimilation feature that you don’t already have

Into the Mist

You may pick an additional Wraith assimilation feature that you don’t already have. As more of your body is now assimilated with the wraith within you are surrounded by a ghostly fog in a 10 ft radius. All ranged attacks made against you are made at disadvantage.

Deathly Chill

You may pick an additional Wraith assimilation feature that you don’t already have. The fog surrounding you now has the chill of death. As an action you can cause the fog surrounding you when a creature first walks through the fog or starts its turn in the fog to take 3d4 cold damage. The duration of this feature is equal to your charisma modifier in minutes.