Black Box

You can create incredibly tough black cube barriers.

Cursed Energy
Starting at 1st level, you can harness your negative feelings into a usable source of energy, called cursed energy. These feelings can be harnessed into attacks or abilities. The number of cursed energy you possess is based on your class, some classes use a modifier that being charisma or wisdom (Player’s choice)

Your cursed energy DC is 8 + user cursed energy ability modifier + proficiency bonus.

Dark Cube
Starting at 1st level, you can spend 2 cursed energy as an action to create an immovable 10 feet opaque black cube within 30 feet of you for 1 minute or until you end it as a free action. If a Large or smaller creature is within range, they must make a Dexterity saving throw or be trapped within the cube. A creature inside your cube has full cover against attacks outside the cube and creatures other than you are blinded if there isn’t a source of light inside the cube.

The cube has an AC equal to your Cursed Energy save DC + 5, hit points equal to your proficiency bonus times twice your Cursed Energy modifier and immunity to psychic and poison damage.

Black Box Reinforcement
Starting at 3rd level you can reinforce your barriers with cursed energy. You can spend additional cursed energy up to your Cursed Energy modifier to give your Dark Cube a reinforcement for every cursed energy spent:

Persistence. Your Cube gains 10 additional hit points for every 1 reinforcement, +1 bonus to AC for every 2 reinforcements and lasts an additional minute for every 3 reinforcements.

Toughness. Your Cube reduces all damage taken by 1 for each reinforcement.

Size. For every 2 reinforcements, you can make your Dark Cube 5 feet larger, allowing you to fit more creatures. (10 ft < 15 ft < 20ft)

At 11th level, you can spend up to twice your CE modifier on reinforcements.

Perfect Cube
At 6th level, you have learned to create a nearly indestructible Dark Cube. For an additional 5 CE, you can create a Perfect Cube (this cursed energy counts towards the Cube’s Reinforcements).

Your Perfect Cube has resistance to all damage and ignores features or abilities that deal higher damage against objects and structures or would destroy, see into, or invade your barrier.

Maximum: Midnight Armor
At 11th level, you have learned to manifest your barrier around yourself. You can spend 6 cursed energy as an action to manifest parts of your cube around your body like armor for 1 minute or until the armor is destroyed:

• You gain the hit points of your barrier as temporary hit points.
• Your AC equals your Dark Cube’s AC.
• Your unarmed strikes can use your CE modifier for attack rolls and deal 3d8 + CE modifier necrotic damage on a hit.
• You can spend additional cursed energy up to twice your cursed energy modifier to also gain the benefits of any reinforcement other than Size.

Domain Expansion: Primordial Gap
At 18th level you have mastered your technique, allowing you to expand your domain. In your domain all of your Dark Cubes automatically count as Perfect Cubes. At initiative 20, you create 3 Perfect Cubes, potentially trapping 3 creatures within your domain inside Perfect Cubes. They are treated as having Reinforcements up to your CE modifier. These cubes disappear when your domain ends.