Transference of Life Essence

You target a single creature and relinquish it's life force to heal another creature's injuries. The target permanently takes 6d8 necrotic damage to its maximum Hit Points, and one creature of your choosing, that you can see within range, regains a number of Hit Points equal to two times the necrotic damage you take. If the necrotic damage decreases the target's maximum Hit Points to 0, it dies. If the target is unwilling, it must make a DC18 Constitution saving throw.

If the second creature is dead, has been dead for no more than 24 hours, didn't die of old age, isn't Undead, and their soul is free and willing, then the target returns to life with current Hit Points equal to the Hit Points lost by the first creature.

This spell neutralizes any Poisons and cures normal Diseases afflicting the creature when it died. It doesn't, however, remove magical Diseases, curses, and the like, if such affects aren't removed prior to casting the spell, they afflict the target on its return to life.

This spell closes all mortal wounds and restores any missing body parts.

Coming back from the dead is an ordeal. The target takes a -4 penalty to all Attack rolls, Saving Throws, and Ability Checks. Every time the target finishes a Long Rest, the penalty is reduced by 1 until it disappears.

Casting this spell to restore life to a creature that has died taxes you greatly. Until you finish a Long Rest, you can't cast Spells again, and you have disadvantage on all Attack rolls, Ability Checks, and Saving Throws.