Ancient Shadow Dragon

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

Sunlight Sensitivity. While in sunlight, the dragon has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Shadowborn. The dragon can see as normally through all forms of darkness, magical or not, within 300 ft. including its own darkness.

Enslavement. Any creature that is killed by the dragon's breath weapon instantly becomes a specter under the control of the dragon.

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

Bite. Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit: (2d10 + 7) piercing damage plus (4d6)fire damage.

Claw. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: (2d6 + 7) slashing damage.

Tail. Melee Weapon Attack: +15 to hit, reach 20 ft., one target. Hit: (2d12 + 7) bludgeoning damage.

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 23 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.

Rotting Breath (Recharge 5–6). The dragon exhales fire in a 60-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 63 (22d6) necrotic damage on a failed save, or half as much damage on a successful one. If a creature fails this save, its maximum hp is lowered by an amount equal to half the total damage taken. If a creatures max hp is lowered to 0 by this effect, they die instantly, This effect lasts until the creature receives a long rest.

Shadow Stealth. While in dim light or darkness, the dragon can hide as a bonus action.

Shadow movement. The dragon can double its walking speed for this turn.

Void Shift (Recharge 5-6). After receiving damage from any source, the dragon conjures a black mist to surround the area within a 300 foot radius, imposing disadvantage on all attacks where the attacker relies on sight made against creatures within the mist until the start of its next turn. There is no light within this area, and it cannot be dispersed by any light, magical or not.

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. 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 15 feet of the dragon must succeed on a DC 23 Dexterity saving throw or take 17 (2d6 + 7) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.