Behemoth of the Apocalypse

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

Magic Resistance: The Behemoth has advantage on saving throws against spells and other magical effects.

Magic Weapons: The Behemoth's weapon attacks are magical.

Multiattack: The Behemoth makes five attacks: two with its greatsword, two with its claws, and one with its tail.

Greatsword: Melee Weapon Attack: +25 to hit, reach 15 ft., one target. Hit: 50 (8d10 + 10) slashing damage.

Claws: Melee Weapon Attack: +25 to hit, reach 10 ft., one target. Hit: 30 (4d8 + 10) slashing damage.

Tail: Melee Weapon Attack: +25 to hit, reach 20 ft., one target. Hit: 40 (8d6 + 10) bludgeoning damage

The Behemoth can take 3 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. The Behemoth regains spent legendary actions at the start of its turn.

Attack: The Behemoth makes one greatsword or claw attack.

Hellish Blast (Costs 2 Actions): The Behemoth unleashes a blast of hellish energy in a 120-foot cone. Each creature in that area must make a DC 30 Dexterity saving throw, taking 80 (20d6) fire damage and 80 (20d6) necrotic damage on a failed save, or half as much damage on a successful one.

Teleport: The Behemoth magically teleports, along with any equipment it is wearing or carrying, up to 120 feet to an unoccupied space it can see