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

Abyssal Lash. Any demon within 5ft of the dragon can use an action to jab a painful spike into the dragon causing (1d10) damage, and will allow the dragon to make a melee attack as a reaction.

Legendary Resistance (1/day). If the dragon fails a saving throw, it can choose to succeed instead.

Multiattack. The dragon can use its Frightful Presence. The dragon makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 15 (2d10 + 6) piercing damage plus 4 (1d8) cold damage.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 6) slashing damage.

Tail. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d8+ 6) bludgeoning damage.

Abyssal Frost Breath (Recharge 5–6). The dragon exhales an icy blast in a 30-foot cone. Each creature in that area must make a DC 15 Constitution saving throw, taking 20 (5d8) cold damage; and taking 20 (5d8) necrotic damage on a failed save, or half as much damage on a successful one.

Frightful Presence. Each creature that is within 120ft of the dragon and are aware of it must succeed a DC 14 Wisdom saving throw or become frightened for 1 minute. A creature can repeat this saving throw at the end of each of its turns.The creature is immune to the effects for 24 hours once it ends or if the creature succeeded the save.