Path of the Lich

A wizard variant of some of the better ideas for a Lich subclass from other classes.

Spirit Vessel

Starting at 2nd level whenever you cast a spell you gain a number of temporary hit points equal to the spell level plus your spellcasting modifier. These temporary hit points are not consumed before regular hit points stack with any temporary hit points gained from this subclass but not with any other source. In addition, you treat any magical healing as if it were radiant damage, however any necrotic damage instead restores an equal amount of hit points. You lose all temporary hit points gained from Spirit Vessel on a short or long rest.

Vestige of Life

Starting at 2nd level, whenever a creature that isn't an undead or construct dies within 30 feet of you, gain temporary hit points equal to half your spellcasting modifier (rounded up).

Additionally, whenever a creature more than 30 feet away that isn't an undead or construct is reduced to 0 hit points by damage caused by you, gain temporary hit points equal to your spellcasting modifier.

Temporary hit points gained this way are treated as if gained through Spirit Vessel, and are lost after the end of a short or long rest.

Lich's Mark

Starting at 6th level, you can mark a creature as a bonus action a number of times equal to your proficiency bonus. While marked a creature has disadvantage on all constitution and wisdom saves against your spells. When a marked creature is slain it immediately reanimates as an undead under your control. You regain all uses of this ability on a long rest.

Life Conversion

Beginning at 10th level, you gain the ability to convert hit points, including temporary hit points, into spell slots. 

Use the expanded table below to determine the costs:

(Temporary) Hit Points       Spell Slot

                  10                             1st

                  15                             2nd

                  25                             3rd

                  30                             4th

                  40                             5th

 

Death Denied

Starting at 14th level, when you drop to 0 hit points, you can make a constitution saving throw with a DC of 20 minus Constitution bonus and your proficiency bonus (20 - (CON + PB). If you succeed, you drop to 1 HP instead. Every time you succeed, the DC increases by 5. The DC resets after you finish a short or long rest. This feature has no effect if you are reduced to 0 hit points by radiant damage, in an area that is consecrated, or are under the effects of a bless spell.