Ultimate Life Transference

You sacrifice some of your health to mend another creature’s injuries. You take 4d8 + your spellcasting modifier in necrotic damage, which can’t be reduced in any way, and one creature of your choice that you can see within range regains a number of hit points equal to four times the necrotic damage you take.

Alternatively, if the target creature has died within the last minute, you can sacrifice half of your hit points to bring them back to life with a number of hit points equal to what you gave up.