Countdown

You conjure a spectral face of a cloak centered on a point on a solid surface you see in range. The clock's face projects a 50ft radius, a 100ft high cylinder of inevitable energy, and shows 12:00. At the end of each of your turns, roll d4. The clock ticks backwards a number of hours equal to the result, and each creature within the area takes 1d12 thunder damage for each hour ticked by.

A creature within the spell's area is Doomed. The Doomed condition is detailed in the Appendix of Bigby's Glory of the Giants or at this spell's end. If the time on the clock shows 08:00 or earlier, creatures in the spell's area have their speed halved. If the time on the clock is 04:00 or earlier, creatures in the spell's area can't react, can use an action or bonus action, not both, and if they attempt to take an action, they must roll a d20. On a 11 ≥ , the action doesn't take effect until the creature's next turn.

If the clock reaches 00:00, each corpse and Doomed creature in the spell's area is permanently frozen in time. A target frozen in time this way is immune to all damage, can't be moved, and can't be returned to normal by any means short of a Wish or Dispel Magic cast at 9th level.

Doomed: A doomed creature can't regain or have temporary hit points. The creature has disadvantage on saves against damaging effects. Typically effects that inflict doom come with the ability to end the condition or inflict the condition for a limited duration. For those who want to get rid of it quickly or are afflicted with a permanent form, a Greater Restoration or similar can remove Doomed.