Elkenflower's Hourglass

You draw a living creature into a prison of glass and sand. Choose a creature within range of Large size or smaller that has been alive for less than 1,000 years. The target makes a Wisdom saving throw; on a successful save, the creature is unaffected, and is immune to the spell for 24 hours. On a failed save, the creature is restrained and held in place as their flesh begins to crumble and break. 

If you maintain concentration on this spell until the end of the creature’s next turn, it must make another Wisdom saving throw. On a successful save, the spell ends, and the creature is immune to the spell for 48 hours. On a failed save, the creature's body is transformed into several thousand grains of sand, and bound within the hourglass for 10 minutes. Each grain of sand represents one day of the creature's life. The size of the hourglass magically alters to accommodate for larger or smaller quantities of sand.

A creature bound within the hourglass cannot see, speak, or hear. It is incapacitated, and any equipment being worn or carried by it merges into its form during the course of the transformation. Equipment that merges into this form cannot be used, wielded, or otherwise activated until the spell ends. The creature doesn't need to breathe, eat, or drink, and it doesn't age. The hourglass is a Tiny object with AC 16 and 12 hit points. It gains resistance to all forms of non-magical damage, and immunity to poison and psychic damage. If the hourglass is reduced to 0 hit points, it is destroyed, and any living creature held inside is immediately released into an unoccupied space within 5 feet. As an action, you can cause the hourglass to spin rapidly in place, ravaging mind and soul as the creature held within is cast back and forth through time. The creature takes 4d6 force damage and 6d6 psychic damage, and must make a Wisdom saving throw. On a successful save, the hourglass is reduced to 0 hit points.

If the creature is reduced to 0 hit points, the hourglass is shattered and destroyed. The creature, and any equipment being worn or carried by it, is reduced to a small pile of sand. The creature can be restored to life only by means of a true resurrection or a wish spell.

At Higher Levels: When you cast this spell using a spell slot of a higher level, the creature is contained for a greater length of time. This time increases to 1 hour with a 7th-level slot, to 24 hours with a 8th-level slot, and to 12 days with a 9th-level spell slot.