Dark Necromancy

As a Warlock of the fiend you draw dark Necromancy power from your patron. You can decompose living matter, manipulate souls and create powerful undeads no other mortals could normally create.

 

Innate Destruction

Starting at 1st level, when you cast a spell or cantrip that deals necrotic damage, you can add your charisma modifier to one damage roll of that spell or cantrip.

Devour Soul

At 1st Level, your patron has given you the ability to devour souls. You gain a pool of soul points, you initially have 0 soul points. Your Maximum soul pool is equal to your level. You can use your reaction to take a soul from one creature that is being killed, that isn't undead or a construct (of challenge rating more than 0) within 30ft of you, when you do this, you recover hit points equal to your proficiency bonus and add one soul point to your soul pool. If the soul devoured creature is brought back to life by any means, you feel it and know it (you don't know any detail of how and where it was brought back to life), but you do not lose your soul points as you have already extracted some of the essential energy from them. You can use each soul point to gain an additional proficiency bonus to your hit points, or use more than one soul points to add one point to your AC.

Enhanced Minions

At 6th level, you add the Animate Dead spell to your spell list and it counts as a Warlock spell for you. When you cast Animate Dead, you can target one additional corpse or pile of bones, creating another zombie or skeleton, as appropriate.

Whenever you create an undead using a necromancy spell, it has additional benefits: The creature's hit point maximum is increased by an amount equal to your Warlock level. The creature adds your proficiency bonus to its weapon damage rolls.

Master of Souls

At 10th level, you gain resistance to necrotic damage, and your hit point maximum can't be reduced. Also, you add the Create Undead spell to your spell list and it counts as a Warlock spell for you.

Recycle Life

Starting at 14th level, whenever you create undeads using a necromancy spell, instead of creating 2 creatures, you can spend 1 soul point to create one stronger creature infused with an artificial soul. You can also reassert control over 1 stronger creature instead of 2 normal ones without spending soul point. When you create it, its body appearance changes to your desire, but this change can't affect creatures functionality drastically (you can change skeletons into meaty demon, or beautiful fey, but you can't make it quadrupedal.). it has same statistics as the initial one, except it has the following additional features:

The creature's hit point maximum is increased by an additional amount equal to your Warlock level. The creature adds half of your proficiency bonus to its weapon attack rolls, all its saving throws and its AC (rounded down).The creature's movement speed is increased by 10 feet.Creature Intelligence, Wisdom and Charisma becomes 10 if they were bellow that value, and it learns to understand and speak one language you know.

You can remove traits from its stats block. (for example: Sunlight Sensitivity trait for Wights, or Stench trait for Ghasts)The creature Type changes into one of following: Undead, Fiend, Fey, Aberration, Monstrosity (your choice). You can also chose its size between: Small, Medium, Large.You can chose any alignment for creature.

Pinnacle of Immortality

At 14th level, You stop aging, and you no longer need to breathe, sleep, eat or drink to survive. You still need to take a long rest by meditating or doing any light activity (like reading, keeping watch, etc.) to restore hit dice, and recover Exhaustion level.