Sacrificial Healing

4th-level necromancy (ritual)
Casting time: 1 action
Range: Touch
Target: a willing creature in range
Components: V, S, M (a silver knife)
Duration: Instantaneous
Classes: Bard, Sorcerer, Wizard
Subclasses:

You heal another creature’s wounds by taking them upon yourself or transferring them to another willing creature in range. Roll 4d8. The number rolled is the amount of damage healed by the target and the damage you take, as its wounds close and similar damage appears on your body (or the body of the other willing target of the spell).