Void Heart

You have learned to harness the soul of your enemies and infuse it with void, a dark emptiness, to utilize it, gaining the upper hand in battle.

Soul Reaper

You have learned to harness the souls of your enemies. Starting at 3rd level, whenever you hit a creature that has a CR higher than 0, you gain 1 Soul Point. You can only have a maximum of 3 Soul Points at once. The maximum number of Soul Points you can have at once increases by 1 at 8th, 13th, and 18th level.

The soul of your enemies cannot be held inside you indefinitely. You lose all of your soul points upon a short or long rest.

Manifest Soul

You have the ability to use the soul inside of you to manifest powers. At 3rd level, you learn two of the following soul manifestations, and learn one more at levels 7, 10, and 15. In addition, you can change one of the soul manifestation options that you know when you gain a level in this class.

If an ability requires a creature to make a saving throw, the DC equals 8 + your proficiency bonus + your CON modifier.

Focus Soul
As a bonus action on your turn, you can spend 3 Soul Points to use your Second Wind feature, even if you have already used it.

Vengeful Spirit
When you take the attack action on your turn, you can spend 1 Soul Point to replace an attack with a blast of soul. Make a ranged spell attack against one creature within 30 ft. of you that uses your CON modifier. On a hit, the target takes 1d8 + your constitution modifier force damage.

Desolate Dive
As an action on your turn, or as a reaction to falling more than 10 ft., you can spend 2 Soul Points to slam into the ground and create a blast of soul. If you use this as a reaction, you fall to the ground and take no falling damage, in addition to the normal effects. All creatures within 10 ft. of you must make a Dexterity saving throw, or take 1d8 force damage and be pushed 10 ft. away from you.

Soul Dash
As a bonus action on your turn, you can spend 1 Soul Point to move half of your movement speed without taking opportunity attacks.

Dream Soul
As an action, you can spend 3 Soul Points to cast detect thoughts 

Resting Soul

You have become able to hold onto soul for longer periods of time. When you take a short or long rest, you can keep a number of Soul Points equal to half of your maximum, instead of losing all of them.

Manifest Void

You learn to empower the soul within you with void, an empty darkness. All of your current features from Manifest Soul, and any that you take at higher levels, are upgraded to the followeing:

Dark Rejuvenation
Required: Focus Soul
When you use your Focus Soul ability, it costs 2 Soul Points instead of 3.

Shade Soul
Required: Vengeful Spirit
When you use your Vengeful Spirit ability, it targets a 30 ft. long, 5 ft. wide line instead of one target. Anyone in the area makes a Dexterity saving throw instead of you making an attack roll.

Descending Dark
Required: Desolate Dive
When you use your Desolate Dive ability, the ability extends to 15 ft., and a creature also falls prone on a failed save.

Shade Cloak
Required: Soul Dash
When you use your Soul Dash ability, you can move through hostile creatures spaces as part of the movement, but cannot end the movement there. After you use your Soul Dash ability, you gain resistance to the next melee attack that hits you this round.

Void Mind
Required: Dream Soul
When you use your Dream Soul ability, it costs 2 Soul Points instead of 3. In addition, you do not need to use concentration when casting detect thoughts with it.

Potent Void

Your void infused soul becomes more potent, causing more pain to those it is inflicted upon. All of your Void Manifestations that deal damage deal an additional 1d8 Necrotic or Radiant damage.

Born of Soul and Void

The void infused soul in you has grown so that even when you die, the soul and void lives on. When you die, a being of soul and void appears from your corpse in the nearest unoccupied space, and it looks like an inky version of you, and disappears after 1d4 rounds. It rolls initiative, and you control it. At the start of its turn, it gains 2 Soul Points. On its turn, it can move up to your move speed, and use any of your Void Manifestation features. If a spell that would bring someone back to life is cast on it, you come back to life. When you come back to life in any way, it disappears.