Nihilomancy

Nihilomancy, as opposed to necromancy, is solely concerned with the study and use of negative energy. They are adept at divorcing life from living flesh, earning them quite a reputation for evil-- and indeed, most nihilomancers tend towards evil. One would be hard pressed to find tomes devoted to this school in most wizarding schools, though those of the udadrow and other traditionally “evil” societies will certainly contain such knowledge.

Harm Touch

2nd-level Nihilomancy feature

At 2nd level you can conjure minor deathly energies to your palm, making you able to deal death with a touch. As an action, you can make a melee spell attack against a creature within 5 feet of you. On a hit you deal necrotic damage equal to twice your wizard level. This counts as a cantrip for the purposes of it being classified as a “spell.”

Nihilomancy

2nd-level Nihilomancy feature

Also at level 2 you gain the plumb depths of necromantic knowledge beyond that of normal wizards. You can learn necromancy spells from any other class's spell list, both on level up and from spell scrolls.

Ennervation

6th-Level Nihilomancy Feature

 At 6th level when you deal necrotic damage to a creature with a spell of 1st level or higher, they must make a Constitution saving throw (if the spell requires a Constitution saving throw, use the creature's save for the spell) or be weakened until the end of their net turn. Weakened creatures cannot add either their Strength or Dexterity modifier to damage they deal with weapon attacks. If a creature succeeds on this saving throw, they are immune to it for 24 hours.

Potency

10th-Level Nihilomancy Feature

Starting at 10th level, any spells you cast dealing necrotic damage have your Intelligence modifier added to them.

Interitus

14th-Level Nihilomancy Feature

Beginning at 14th level you can sacrifice your own vitality, transforming it into negative energy. When you cast a spell dealing necrotic damage, you can spend wizard hit dice up to your Intelligence modifier, rolling each one. You suffer unavoidable necrotic damage equal to the amount rolled, subtracting it from your hit point maximum. Add twice the amount rolled to the damage of the spell.

Your hit point maximum is restored upon completion of a long rest, or by the casting of a wish spell.