MonkeyDM
Level 4 Conjuration (Osteomancy) (Warlock, Wizard)
Casting Time: Action
Range: 60 feet
Components: V, S, M (a virgin’s carpal bone)
Duration: 1 minute
A creature within range must succeed on a Strength saving throw or be trapped inside an iron maiden formed of bone that appears in its space. The creature has the Restrained and Incapacitated conditions, is behind Total Cover, can’t be damaged by attacks or effects originating from outside, and takes 3d6 Piercing damage at the start of each of its turns as spikes of bone pierce its body.
At the end of each of its turns, a trapped creature can repeat the saving throw, escaping and ending the spell on a success.
The bone maiden has AC equal to 10 plus your spellcasting modifier, 80 Hit Points, Immunity to Psychic and Poison damage, and Vulnerability to Bludgeoning damage. If the maiden is destroyed, the creature trapped inside is freed and the spell ends.
Using a Higher-Level Spell Slot. The damage increases by 1d6 and the maiden’s Hit Points increase by 20 for each spell slot level above 4.