Create Philosopher's Stone

As you cast the spell, you draw two 5-foot-diameter circles on the ground with the blood of a willing participant (which could be yourself), inlaid with hemomantic sigils detailing the runes of life and death. In the center of one circle stands the willing participant whose blood was used to draw the circles and in the other, a ruby.

Then by reciting ancient words of power you imbue the ruby with the vitality of the participant. You expend a number of Hit Dice from the creature, for each one expended their Maximum Hit Points are reduced by the maximum number that is on the die. A creature that is brought to 0 Hit Points in this way is utterly destroyed, as if struck by the Disintegrate spell. The creature’s Maximum Hit Points are returned to normal after 1d4 Long Rests, or 2d4 if more than half their total Hit Dice were expended.

The vitality extracted is then imbued into the ruby, transmuting it into a Philosopher’s Stone containing the creatures expended Hit Dice.