Cryotomb

All Spells

Ice Spell, Tier 8, 4 Actions, Secret

Range: 12. A target must make a STR save or become incapacitated in an icy tomb and immune to harm. This lasts as long as you remain alive, or until the ice melts or is otherwise destroyed. The creature may repeat the save once every 10 days. Huge or larger creatures have advantage on the save. Small or Tiny creatures have disadvantage. Upcast: +5 spell save DC.

Why is this secret? Being able to instantly trap any boss who fails a single roll is incredibly useful. Cryotomb is even more useful as a narrative linchpin though. For example, the king may have a terrifying monster sealed in ice beneath the palace—and the tomb is beginning to crack…

From Game Master's Guide