• Legendary Resistance (3/Day): If the dracolich fails a saving throw, it can choose to succeed instead.
• Magic Resistance: The dracolich has advantage on saving throws against spells and other magical effects.
• Multiattack: The dracolich can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.
• Bite: Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 18 (2d10 + 7) piercing damage plus 5 (1d10) lightning damage.
• Claw: Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage.
• Tail: Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 16 (2d8 + 7) bludgeoning damage.
• Frightful Presence: Each creature of the dracolich's choice that is within 120 feet of the dracolich and aware of it must succeed on a DC 18 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 dracolich's Frightful Presence for the next 24 hours.
• Lightning Breath (Recharge 5-6): The dracolich exhales lightning in a 90-foot line that is 5 feet wide. Each creature in that line must make a DC 20 Dexterity saving throw, taking 66 (12d10) lightning damage on a failed save, or half as much damage on a successful one.
The adult blue dracolich 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 adult blue dracolich regains spent legendary actions at the start of its turn.
• Detect: The dracolich makes a Wisdom (Perception) check.
• Tail Attack: The dracolich makes a tail attack.
• Wing Attack (Costs 2 Actions): The dracolich beats its tattered wings. Each creature within 10 ft. of the dracolich must succeed on a DC 21 Dexterity saving throw or take 14 (2d6 + 7) bludgeoning damage and be knocked prone. After beating its wings this way, the dracolich can fly up to half its flying speed.