Radiant Moon Crystal (5e Equipment)

Wondrous item, legendary (requires attunement by a spellcaster)

Moon crystals are dew-covered stones that form at the mouth of caves, whilst covered in the light of a full moon. Under perfect conditions, a rare radiant moon crystal can form—an artifact capable of storing and harnessing the souls of creatures.

Soul Vessel. A radiant soul crystal can hold a number of souls with combined challenge rating less than or equal to the crystal's maximum capacity, which is equal to 2d4 + 2 when first found.

Imprison Soul. As an action, you can expend a spell slot to utter a word of power that binds a creature to your will, imprisoning it inside the crystal used in the spell's casting. Target a creature within 120 feet of you that you can see. If its hit point maximum is less than 10 time the level of the expended spell slot, it gets sucked into the radiant moon crystal, its soul becoming bound to it.
While you have a creature bound to a crystal this way, you can use your action to summon an apparition of it in an unoccupied space within 30 feet of you that you can see, or to dismiss such an apparition. This apparition uses the statistics of the creature it is based off of. On each of your turns, you can use your bonus action to mentally command an apparition you control. You decide what action the creature will take and where it will move during its next turn, or you can issue a general command, such as to guard a particular chamber or corridor. If you issue no commands, the creature only defends itself against hostile creatures. Once given an order, the creature continues to follow it until its task is complete.
You cannot summon more than one apparition from the same crystal at a time. An apparition lasts until 24 hours pass, it is destroyed, or you dismiss it as a bonus action.
If a creature's apparition is destroyed, or disappears after 24 hours pass, it escapes from the crystal and appears in an unoccupied space adjacent to the crystal.
Destroying the Radiant Moon Crystal. A radiant moon crystal will crack and shatter if you try to put more souls into it than it can physically bear. When a radiant moon crystal is destroyed, all of the souls trapped within are released, causing each of those creatures to reappear in the nearest available unoccupied spaces.