Bluestone's Doppel

This spell grows an inert duplicate of a living creature. This doppelganger forms inside the vessel used in the spell’s casting and grows to full size and maturity after 1 year. After maturing, the vessel shatters, and the new creature is released.

The doppel is physically identical to the original and has the same personality, memories, and abilities, but none of the original's equipment. Additionally, doppels, while seperate and fully developed creatures, are unable to cast spells to awaken, animate, heal, replicate, clone, duplicate, revive, resurrect, or otherwise give life.

If a doppel is reduced to 0 HP, it permanently dies. It is unable to be revived or resurrected, and cannot be targeted by divinatory spells such as speak with dead. It's remains turn into a fine dust, and the doppel drops everything it is carrying and wearing.

After successfully casting doppel, the caster must succeed a DC 25 Constitution save or become stupefied for 1d3 days. A creature that succeeds is not stupefied. Stupefied creatures take a -2 status penalty on Intelligence, Wisdom, and Charisma based ability checks, saving throws, and spell attack rolls. Any time you attempt to Cast a Spell while stupefied, the spell is disrupted unless you succeed a spellcraft check with a DC equal to 10 + the spell's level. While stupified, Constitution saving throws made to maintain Concentration are made at disadvantage. Additionally, the stress of casting this spell to produce any effect other than duplicating another spell weakens you, as the caster sacrifices a piece of themselves to seed a new soul. After enduring this stress, each time you cast a spell until you finish a long rest, you take 2d10 necrotic damage per level of that spell. This damage can't be reduced or prevented in any way.