Cryovain (Revamped)

Ice Walk The dragon can move across and climb icy surfaces without needing to make an ability check and, difficult terrain composed of ice or snow doesn't cost extra movement.

Legendary Resistance (3/Day) If it fails a saving throw, it can choose to succeed instead.

First Attack: Cryovain will use Frightful Presence and then if anyone in range makes the save he will target them with a bite and then tail attack before taking to the air to set up for a Cold Breath for the next turn. If all fail in range, he will NOT make an attack but will take to the air and line up to hit the most people with a Cold Breath.

Multiattack Cryovain makes three attacks: one of each or one bite and two claws. He will attempt to attack multiple creatures if in range but if a creature does 40 points of damage in one round, Cryovain will become furious and spend the next turn attacking that sole creature. If multiple do, whoever is the last to do the required damage will be targeted as Cryovain is quick to anger and has a short memory when furious.

Bite Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 4 (1d8) cold damage.

Claw Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage.

Tail Melee Weapon Attack: +10 to hit, reach 15 ft., one target. Hit: 15 (2d8 + 6) bludgeoning damage. Those hit must make a DC 15 strength saving throw or be thrown 20 ft and knocked prone.

Frightful Presence. Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 14 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Cold Breath (Recharge 5–6). The dragon exhales an icy blast in a 30-foot cone. Each creature in that area must make a DC 17 Constitution saving throw, taking 40 (8d8) cold damage on a failed save, or half as much damage on a successful one.

The dragon 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 except under certain circumstances with Frost Blast Slam. The dragon regains spent legendary actions at the start of its turn.

Detect. The dragon makes a Wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 10 feet of the dragon must succeed on a DC 16 Dexterity saving throw or take 13 (2d6 + 6) bludgeoning damage and be knocked prone and 10 ft away. The dragon can then fly up to half its flying speed and does not provoke attacks of opportunities.

Frost Blast Slam(Costs 2 Actions):   Cryovain must be 20 feet in the air to make the slam. He can move up to 20ft from his position to make the slam. If an attack will bring him to the ground, he can use this action and not have to wait for the end of the creatures turn. Just before he slams on the ground he shoots a cold breath at the ground which is then pushed out in a 30ft sphere. Any creature within 30 ft of the slam must make a DC 15 Strength save with disadvantage if on ice or other slippery surface. On failed save, they are pushed back 30 ft and knocked prone, taking (13) (2d6 + 6).  On success they are pushed back 15 ft, NOT knocked prone, and taking half damage.  If a creature is about to go off a cliff they can make a DC 10 Dex save to catch the ledge. If a creature hits a wall or other object that would stop them from moving, they take (d6) Bludgeoning damage for every teen feet they moved.
The cold breath recreates a 30 ft square of ice on the ground, if there wasn’t any before.