Chronos Contingency

Legendary Resistance (5/Day). If CC fails a saving throw, it can choose to succeed instead.

Magic Resistance. CC has advantage on saving throws against spells and other magical effects.

Reactive Carapace. Any time CC's targeted by a magic missile spell, a line spell, or a spell that requires a ranged attack roll, roll a d6. On a 1 to 5, CC is unaffected. On a 6  CC is unaffected, and the effect is repulsed back at the caster as though it originated from CC, turning the caster into the target, doubling any Damage, area of effect, or Condition Duration.

Siege Monster. The tarrasque deals double damage to objects and structures.

 Heart of Wrath. Chronal Terrasque Restores 100d100, roll a d100  Hit Points.

• Multi-Pantheon Panacea, The Plane of PAIN. Deities Devolved this Praetorian Power, Separated from the Colossus Construct created by Primus for Protecting Reality from unbridled Deviant Desolation. Unbidden, doom carried on, irreverent Menace wearing a clandestine Countenance. The Divine Council bound forces together to Asmodeus' Lords of Bator for the Carnage arcana Unearthly Transmogrified and placed to Stasis Twin engines of Desolation. Awaiting the Spark!
• An Avatar of Moradin in Dwarven Hearth Awakens the twin Terrasque (Adamantine & Nova Variant Titled The Chronos Contingency! Attenuated to The Demi plane Chronos~! Where by the God's could accurately Decree the Moment Chronos' Paragonical Feat finally completed, realizes his fraudulent Frenzy in fact, the God's final act of desperation,  & Synchronous  CC killed by the Emblazoned Prime Plane Denizens daring defend Fearun from volcanic stratosphere terraforming terrasque. 
• Decline as undoing; Suffering unabashed Divine torture during the course of every 6 seconds 100d100 "Life counters"{Hit point's} stripped away to respawn as soon as removed. (Restoration         occurs on init 20(losing ties) while Damage is per turn (portions equaling total damage divided by number of turns  combatants take actions as participants to the Encounter subtracted at the end of each other combatants turns.
• Coronary Aurelius Lifeforms begin acquiring Magical Fire Damage 50 miles away! 10d10, DC26 or ignite[5d6 per turn till extinguished
• 10 Miles distance; 10d% DC34 or Engulfed 3d% per turn, requires 1gallon of water per damage point submerged entirely for complete round to extinguish.
• melee to 10 miles; 100d100, DC42 or Emblazoned 10d100 per turn. Requires hit points remaining amount able to soak the same damage just taken, or humanoid torch Flames on! Submerged 1 round per 100 hp damage, 1 gallon per hp damage to extinguish Emblazoned condition.
• Finger the Forge; upon any contact victims instant permanent vulnerable to Fire

More Pain as the Source rolls ever onward , as a Bonus action ChronolTerrasque may suffer continued Godly Fury, a fierce representation of the Titanic Conflict as Chronos slays Deity upon corpse of Deity; One by One, till Deicide is undergone ritualistically in it's entirety! Where-upon, that very Moment of Chronos' cognitive awareness the depth of planer Residence. Prophecy or not, He will brake free. The Deicide has not yet Begun!

5 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn^ regains spent legendary actions at the start of its turn.

Attack.make one claw attack or tail attack.

Move.  moves up to half its speed.

Chomp (Costs 2 Actions). makes one bite attack or uses its Swallow.