Shadow Knight fighter

This is a character from a book from Branden Sanderson in dnd the book is cald steel hart go read it.

Night Wielder is a person in the reckoners series from Brandon Sanderson who can create and control a black substance that he uses to kill people. There are multiple things a person needs when he takes the subclass to feel more like Night Wielder you do not need it per say to for this to be a strong subclass.

Shadow mastery

When you choose this archetype at third level you gain the ability to (non-magicly) create a substance that you can control. You can do the following with it:

simple items

You can create any (non-magical) item that is smaller than 5 by 5 feet. This item does not have any value and is not made of any material. You can dismiss it without an action. The items can not move more than thirty feet away from you.

armor and weapons

You can create any armor and weapons you are proficient in with the same limits as the simple items. They can not move more than thirty feet away from you.

wall

You can create a wall of a maximum of 5 by 5 feet. You can move it up to 30 feet in a round if it hits something it deals 1d6 damage in force. The wall has an AC of 16 and 5 times your prof bonus in hitpoints.

chains

You summon chains to insnair an opponent they target must make a dex save and on a failed save they are restrained and incapacitated they can free themselves by succeeding on a strength check. The DC for the strength and dex checks are 8+prof bonus+strength mod. They can also be free by a different creature. The creature must destroy the chains they have an AC of 16 and 5 times your prof bonus in HP. 

weapon attack

You make a weapon attack on a creature you can see within 50 feet (you can use strength or dex for this attack) on a hit the target takes 2d6+ strength mod/dex mod in force. This is instead of a normal attack. This is instantaneous and does not count towards the amount active at once.

 

pick up

You pick up an object of a maximum of 5 by 5 feet you can move this object up to 30 feet in any direction if you do this with a creature they must make a dex save or be picked up.

 

You can have your prof bonus of these items active at once.

If you create an object in a creature's space and they are not damaged or incapacitated by the object they are pushed aside and take 1d4 force damage.

Shadows might

You can create an infinite amount of simple items, armor, and weapons that will disappear after being used for more than one hour by a creature that is not you. It can now move anywhere.

These do not count towards the items that you can have active. You also become proficient with any item you create which lasts for one hour.

Shadow Wall

You can when you are attacked by a melee attack use your reaction to create wall.

This functions as if you used your bonus action to create it.

You also gain these new abilities.

knock

You shoot a wave over the ground in a 20-foot cone; any creature it hits must make a dex save or be knocked prone and take 2d6 damage.

 

crush

You try to crush an item or creature the creature you try to hit must make a dex save and on a fail they take 2d10 force and on a success they take half as much. If it is an object that cannot move it takes double damage. The range is 30 feet. This is instantaneous and does not count towards how many are active at once.

 

Shocking Wave

Once a day you send out a wave of destructive power allowing you to place any amount of object from your third-level (you cannot use knock or crush) ability in a fifth-foot cube around you that lasts for ten minutes. Each object takes up one square of five by five feet of space.

If you use any ability that is not instantaneous it lasts for ten minutes if it is instantaneous it disappears after it is used. If the item you created lasts longer than ten minutes it instead lasts its full duration.

Pick up last ten minutes.

Creature of Shadow

When you use one of your shadow master abilities (including crush and knock) you can use a second one also you can use shocking wave twice per day. You can now also use crush and knock with shocking wave.