You evoke a large quantity of Oblivion energy below the ground such that the ground above it becomes unstable and suddenly crumbles and sinks into a pit 100 feet deep. A creature standing on a spot where a sinkhole opens must succeed on a Dexterity saving throw or fall in and take 10d6 bludgeoning damage. A creature that successfully saves moves with the hole’s edge as it opens.

Any structure over the radius that’s completely within the radius of the sinkhole automatically collapses into the hole. A structure that overlaps the sinkhole radius takes 10d10 bludgeoning damage. If a structure reaches 0 hit points, it collapses into the hole. A creature that falls into the hole or is inside the structure must make a Dexterity saving throw. On a failed save, the creature takes 5d6 bludgeoning damage in addition to the falling damage, is knocked prone, and is buried in the rubble, requiring a DC 20 Strength (Athletics) check as an action to escape. The GM can adjust the DC higher or lower, depending on the nature of the rubble. On a successful save, the creature takes half as much damage and doesn't fall prone or become buried.