I am DMing a level 20 "3-shot" set in the present day. I am trying to run the sessions as RAW as possible.
After our first session, a player whose character can cast True Polymorph wanted to polymorph a Commoner NPC into a stronger creature so they could enlist them to their cause.
The True Polymorph spell prevents turning one creature into another, more powerful, creature. However, the player asked if he could get around this by turning the target into an object first.
My instinct says that he could potentially do that, but by True Polymorphing a creature into an object – say, a rock – it becomes a rock. Therefore, when you cast it again it is functionally no different than casting True Polymorph on a rock to start with, meaning the creature has no memories of who or what they were as a human.
How would this work, by RAW?