Necromancer

Your innate magic comes from dark sorcery of death and disease. You might have been part of a necromantic ritual or been experimented on by a litch. Maybe your dark magic is a result of a curse upon your family. This magic yearns to be used to corrupt, kill, and raise as undead. Though your magic is evil in nature, It does not necessarily make you evil as well. Maybe you fight this curse and avoid succumbing to it.

Secrets of necromancy

starting when you choose this origin at 1st level, you gain access to additional spells of necromancy. Choose necrotic, cold, or poison damage. Spells that deal that damage type are considered to be on the sorcerer spell list and count as sorcerer spells for you, and you can learn them as normal. If they offer a choice of damage type, you must chose the damage type you selected from cold, necrotic, or poison. Animate dead, speak with dead, summon undead, danse macabre, raise dead, create undead, resurrection, and true resurrection are all considered to be on the sorcerer spell list in the same way.

Draining magic

Starting when you choose this origin at 1st level, You can use necromancy to drain the life force of your enemies. When you deal damage to a creature with a spell of 1st level or higher that deals cold, poison, or necrotic damage, you can forgo dealing some of the damage and instead heal yourself. The spell deals half damage, and you regain hit points equal to the damage dealt (after halving it). You can use this feature an amount of times equal to your charisma modifier (minimum of once). You regain all expended uses of this feature when you finish a long rest.

Combat reanimation

Starting at 6th level, You can hastily reanimate dead creatures to fight for you. When you kill a medium or small humanoid with a spell that deals cold, poison, or necrotic damage, you may choose to immediately reanimate it. If you do so, it rises as a ghoul and acts as if you had cast create undead on it, but you must concentrate on keeping it alive (as if concentrating on a spell), otherwise it immediately dies again. You cannot use create undead to reassert control over it, and it turns back into a regular corpse after 1 minute. You must take a long rest before you can use this feature again.

Greatly improved necromancy

At 14th level, you can create and control more undead than normal. You can reanimate and reassert control over 1.5 times as many undead with animate dead and create undead.

Dark aura

Beginning at 18th level, you can channel your full power into an aura of necromantic energy. As an action, you can create a dark aura centered you with a 60 foot radius that lasts for 1 minute. All undead of your choice in the aura add your proficiency bonus to their attack and damage rolls, add half your proficiency bonus to their ac, and gain temporary hit points equal to your sorcerer level for as long as they are in the aura. All creatures of your choice within the aura take 2d10 necrotic damage at the start of each their turns