You cause a surge of stone to attempt to engulf a Large or smaller creature in stone. The target must make a Dexterity saving throw. On a failure, they become restrained and blinded in the stone coffin. A creature can choose to fail their save. While trapped within the coffin, they have total cover against all sources. The coffin has an AC of 15 and 50 hit points, and resistance to all damage beside bludgeoning and thunder damage. When the spell ends or the coffin is reduced to 0 hit points, it crumbles to fragments and the creature within is no longer restrained and blinded.
For the duration of the spell you can use your bonus action to attempt to crush a creature encased in the coffin, dealing 1d10 bludgeoning damage.