Specter

You pledge your life to Rhyxali. She holds dominion of the 49th layer of the Abyss: Shaddonon. She does not care much for the matters on the material plane, but by granting her your soul you now must report information and secrets, but are repaid with great power. You are now a demon of the shadows. You can not sleep, eat, drink, or partake in many other pleasures of the living. By trading your life you have doomed yourself to an eternity in Shaddonon. On the other hand, you are immortal. Any "death" in the material plane will send your shadow essence back to the Abyss until you are able to repair or manifest a physical body. Your body is material, yet is also part shadow and you are able to shift yourself into a wraith form. Your physical body has lost all primary features. You no longer have a nose, mouth, ears, hair, or genitalia. Your skin becomes as black as darkness. Your eyes dissolve and turn into empty crevices and a shadowy mist forms, glowing a hue that is reflective of your soul. Your soul wrenching words coalesce from your form itself. Your true form has become a shadowy essence that is merely possessing a material body.  You have gained the ability to consume mortal souls and increase your power with a limitless potential. 

Demonic Arsenal

Due to your new nature, you lose all previous proficiencies related to weapons and armor. Starting at 3rd level, you gain proficiency with the Demonic Arsenal. This arsenal's weaponry is considered magical, but does not gain bonuses to hit or to damage. 

Demonplate armor: 15 AC. A mixture of plate and robes, your new armor has become part of your body. It fully encapsulates you and can not be donned or doffed. 

Abyssal Blades: 2d4 + Dex. Slashing. You gain two retractable blades inside both gauntlets. You are able to extend and retract them as easily as you used to be able to breathe. 

Razor Shuriken: 1d6 + Dex. 30ft/60ft range. Piercing. You keep a oversized razor shuriken on your body. After 6 seconds of being released, the shuriken will dissipate into shadow then reform back on your person. 

Wicked Sickle: 1d8 piercing + *Bleeding. You store a sickle in your shoulder. Temporarily forming part of your flesh into shadow, it does not cause pain or damage when you draw and sheathe the weapon.

Bleeding: If the target is able to bleed, the target will take 1d4 necrotic damage on hit and at the start of each of its turns. The effect lasts until the target or an ally treats the wounds to stop the bleeding with a DC 8 medicine check. On crit, the damage becomes 2d4 on hit and at the start if each of its turns. This effect does not stack.

Shaddonon Native

Starting at 3rd level, you gain multiple effects from your reincarnation. 

Spectral Presence: Becoming part Specter, you gain multiple resistances and vulnerabilities. You are now resistant to cold, poison, and necrotic damage but are vulnerable to fire and radiant. 

Demon Speech: You have been reborn in the 49th layer of the Abyss, gaining an innate ability to speak Abyssal. 

Shadowy One: Being part shadow, you have advantage on stealth when in dim light or darkness.

Blinding Light: Due to your nature, daylight pains you. Your Demonic Arsenal protects you from damage, but the brightness nearly blinds you. You have disadvantage on perception checks in daylight. 

Shadow Clone

Starting at 3rd level, you gain the ability to control a Shadow clone. The clone has 1 hp. The clone shares all the same stats as you. The clone cannot move, but will remain there as long as concentration is kept. This clone takes on a silhouette of your appearance and is a solid form of shadow. The clone has numerous abilities once deployed that will increase as you gain power. 

Throw Shadow: As a bonus action, throw a manifestation of shadow that forms into a mirror image of yourself as the location of impact. The shadow can be thrown up to 10 feet to somewhere you can see.  Once the shadow is deployed, you must stay within 30 feet to keep it active but eyesight is not necessary. 

Shadow Swap: As an action, swap places with your clone. Once your form teleports to the location of your clone, it dissipates. 

Grapple: As a bonus action, your clone can attempt to grapple a hostile within melee range. If the grapple is successful, the clone will hold on until either the target breaks free, or the target is attacked. 

Mirrored Attack: Staring at 5th level, your clone can replicate one attack you take at the same target using the same weapon. Once the attack is complete, the clone dissipates.

Second Nature: By 9th level, you no longer need to concentrate on your shadow clone for it to remain active and the range is doubled. Shadow can be thrown 20 feet and stay active within 60 feet. 

Living Shadow: By 13th level, your shadow clone does not disappear after one action. When using Shadow Swap, your clone will swap locations with you and remains active. 

The Dead are Legion: Reaching level 17, you can now have two shadows active at one time. They also gain a movement speed equal to half of yours. 

One with the Shadows

One with the Shadows: Starting at level 9, gain +10 to stealth in darkness. 

Wraithwalk

Wraithwalk: Starting at 9th level, you can shift into an incorporeal form as an action and become nothing more than a shadowy mist for 12 seconds. While in this form, you cannot be hit, take an action, or be healed. You are not hindered by terrain, can pass through miniscule crevices, and gain the effects of Feather Fall. 

Enhanced Arsenal

Enhanced Arsenal: Starting at 9th level, your armor increases to 17 AC. Your weapons are now magical and add a +1 to hit and +1 to damage. You gain a second Razor Shuriken which can be thrown with the same action as the first.

Binding Darkness

Binding Darkness: Once you reach level 13, you gain +10 to stealth in dim light and become invisible in darkness. 

Death is the Coldest Ice

At 13th level, Death is the Coldest Ice grants you immunity to cold and necrotic damage.

Superior Arsenal

Superior Arsenal: At 13th level, your armor increases to 18 AC. Your weapons now deal +2 extra damage and gain +2 to hit. Your Wicked Sickle bleeding effect can now stack. The medicine check to stop the bleeding increases by 2 for every bleeding stack.

Perfected Arsenal

Perfected Arsenal: By 17th level, your armor increases to 19 AC. Your weapons now deal +3 extra damage and gain +3 to hit. Your Abyssal Blades become 2d6 + dex.

Shadow Slash

Shadow Slash: By 17th level, you can utilize your Abyssal Blades to perform a spinning strike damaging all those within melee range. All those within melee range must make a Dexterity Saving Throw with a DC equal to 8 + Dex Modifier + Proficiency. On a success the target avoids all damage.