*This is not a feat, but a variant class feature available to Wizards specialized in the School of Necromancy. A necromancer may choose this feature at level 2 in place of the Grim Harvest class feature.

At 2nd level, you gain the ability to harvest the souls from creatures you kill with your spells. Once per turn when you kill a creature with a spell that has a single target, you may use a bonus action to gain a number of soul essence equal to half of that creature's hit dice, minimum 1, or equal to its hit dice if the spell belongs to the School of Necromancy. You don’t gain this benefit for killing constructs or undead, nor when killing creatures with a challenge rating of 0. At 10th level, this effect also applies to your spells that affect multiple targets, and you gain soul essence for each creature killed.

You can only possess a maximum number of soul essence at one time equal to twice your Wizard level, and you lose any soul essence in your possession upon dying or completing a long rest.

You may spend your soul essence in the following ways:

• As a bonus action, you may extend the duration of the next Necromancy spell you cast this turn. When you cast the spell, spend a number of soul essence equal to twice the spell's level, or 1 for cantrips, in order to double the duration of the spell. This has no effect on spells that have a duration of instantaneous or until dispelled.
• As a bonus action, you may increase the damage or healing of the next spell you cast this turn. The next time you cast a spell this turn with a duration of instantaneous, you may spend any number of soul essence to increase the healing or to deal extra necrotic damage with that spell equal to the number of soul essence spent.
• As a bonus action, you may spend 4 soul essence to gain a first-level spell slot. This spell slot must be used to cast a Necromancy spell and must be cast this turn or it is wasted. You may also instead choose to increase the level of the next Necromancy spell you cast this turn by spending 6 soul essence for each increased spell level, up to a maximum of level 6. (for example, you can spend a 2nd level spell slot and 12 soul essence to cast blindness/deafness as a 4th level spell)
• As a reaction after suffering damage, you may spend any number of soul essence to reduce the damage taken by twice the number of soul essence spent.
• As an action, you may spend any number of soul essence to heal all undead under your control equal to twice the number of soul essence spent.

At 14th level, you add the soul cage spell to your spellbook if it is not there already, while also gaining additional functionality with the spell.

You may spend 6 soul essence to duplicate either the Steal Life or Borrow Experience effects of the soul cage spell without having cast the spell. While the spell is active, you may also spend 6 soul essence to gain an additional use of a soul trapped by the soul cage spell.

At 14th level, as long as you possess the material components for the soul cage spell, you may now possess a maximum number of soul essence at one time equal to thrice your wizard level, and you retain all soul essence in your possession upon dying or completing a long rest. You also gain 1 soul essence any time you damage one or more creatures with a spell of 1st-level or higher, or 2 soul essence when you damage one or more creatures with a Necromancy spell of 1st-level or higher.