Through years of suffering as a lost soul you've gained supernatural abilities, The darkness is now your friend and you have to rely on it to survive the material plain. While in direct sunlight your AC is reduced by 5 and your vison is considered poor [15 feet sight].This is reverted while in a shadow or dark area.

The shadows casted by objects or creatures are usable as shelter, as an action you can enter a casted shadow or dark area, while inside a shadow you gain advantage on stealth checks and is considered hidden from creatures without darkvison or truesight.

You have the ability to enter an incorporeal and corporeal forms.As an Action you may enter one of these states. An incorporeal creature has no physical body. It can be harmed only by other incorporeal creatures, magic weapons or creatures that strike as magic weapons, and spells, spell-like abilities, or supernatural abilities. It has immunity to all non-magical attack forms.While incorporeal you can attempt to go through walls, if the wall is 5ft to thick you are shoved out and take 1d10 force damage.

Once per day, You can attempt to possess any creatures that are living and not undead, fey, angels or fiends. One humanoid that the shadow can see within 5 feet of it must succeed on a DC 15 Charisma saving throw or be possessed by you, you then disappear, and the target is incapacitated and loses control of its body. You now control the body but doesn't deprive the target of awareness. You can't be targeted by any attack, spell, or other effect, except ones that turn undead, and it retains its alignment, Intelligence, Wisdom, Charisma, and immunity to being charmed and frightened. It otherwise uses the possessed target's statistics, but doesn't gain access to the target's knowledge, class features, or proficiencies.

The possession lasts until the body drops to 0 hit points, you end it as a bonus action, or your forced out by an effect like the dispel evil and good spell. When the possession ends, you reappear in an unoccupied space within 5 feet of the body. The target is immune to your possession for 24 hours after succeeding on the saving throw or after the possession ends. If the creature succeeded on it's saving throw you take 1d10 force damage.

Due to your time in shadowfell you are immune to necrotic and fear effects but are vulnerable to radiant damage.

At 3rd level, Any weapon you obtain gets consumed by your shadow, your shadow weapons are able to be stored in your own pocket dimensional shadow realm and can always appear at-will. You can choose to restore the weapon to its previous state at-will.You gain proficiency bonus with your shadow weapons.

At 10th level, when you succeed on a melee or range attack on a living creature with a shadow you deal an extra 1d8 psychic damage as it's own shadow attacks the creature, if the creature is in darkness they take 2d8 psychic damage.

if the creature dies while attacked by it's own shadow, it re-raises as a shadow. The shadow seeks vengeance and attacks anyone other then you. As a bonus action you can attempt to control the shadow by making a DC 15 intimidation check, if you succeed the shadow is force to obey you until death.

Your life in shadowfell has given you supernatural sight, you have 120 ft darkvison and 25 ft blindsight.

At 9th level, As a bonus action you can cast darkness or invisibility on yourself once per short rest.

At 5th level, Your shadow possess a pocket deminson to your own personal shadow realm, You can store any and all living entities inside the realm as long as it's not bigger then your shadow. At-will you can summon any item you possess from the shadow realm as long as you have a free hand or 5ft space infront of you.

You can attempt to capture a non-willing creature, they must succeed a DC 14 Chrisma saving throw or be consumed by darkness. Captured creatures inside the realm can breathe normally and can make a standard action of DC 18 Willsave to escape the realm.