Earth Glide. The cataclysm can burrow through nonmagical, unworked earth and stone. While doing so, the cataclysm doesn't disturb the material it moves through.
Legendary Resistance (4/Day). If the cataclysm fails a saving throw, it can choose to succeed instead.
Siege Monster. The cataclysm deals double damage to objects and structures.
Control Weather. The cataclysm casts the Control Weather spell, requiring no spell components and using Constitution as the spellcasting ability.
Multiattack. The cataclysm makes two Elemental Burst attacks.
Elemental Burst. Melee or Ranged Attack Roll: +15, reach 30 ft. or range 150 ft. Hit:25 (5d6 + 8) damage of a type chosen by the cataclysm: Acid, Cold, Fire, Lightning, or Thunder.
Cataclysmic Event (Recharge 4–6). The cataclysm creates one of the following effects at random (roll 1d4):
Eruption. The cataclysm makes one Elemental Burst attack.
Rumbling Movement. The cataclysm moves up to its Speed, Fly Speed, or Swim Speed without provoking Opportunity Attacks. Each creature within 5 feet of the cataclysm as it moves is targeted once by the following effect. Constitution Saving Throw: DC 23. Failure: The target has the Prone condition. Failure or Success: The cataclysm can't take this action again until the start of its next turn.
The End and Beginning of Ages