Wealth of Blood

You can cast this spell only as a ritual, with a total casting time of 10 minutes.

Calling on the dark magic of the fey, you sacrifice a creature as a replacement for the materials for a spell. Choose an unconscious humanoid, who must remain within range for the duration of the casting time. When the casting finishes, the target dies and its soul is destroyed, unreturnable except through a wish spell.

Whenever you cast another spell before this one ends, you may choose to forgo using up to 1,000gp worth of the material components for that spell. If you do, this spell immediately ends. Any material component without a gold value for the spell needn't be provided, excepting any component requiring the sacrifice of a soul or the death of a creature as part of the spell's casting. If the spell uses the material component you've forgone in some way, a black, tarlike orb appears in your hand, which takes the place of the material component for that casting and behaves identically to the original.