Armor Class 20 (natural armor)
Hit Points 656 (32d20 + 320)
Speed 60 ft., fly 80 ft. (hover), swim 80 ft.
STR
30 (+10)
DEX
20 (+5)
CON
30 (+10)
INT
26 (+8)
WIS
28 (+9)
CHA
24 (+7)
Saving Throws Dex +13, Int +16
Skills Arcana +16, History +16, Perception +17
Damage Resistances cold, fire; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities lightning, thunder
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, prone
Senses truesight 120 ft., passive Perception 27
Languages Giant, Primordial
Challenge 27 (105000 XP)
Proficiency Bonus +8
Flyby.
Legendary Resistance (6/Day).
Magic Resistance.
Siege Monster.
Multiattack.
Lightning Sword.
Hailstone.
Slam.
Vengeful Storm (Recharge 6).
Acid Rain.
Freezing Storm.
Lightning Bolts.