Adult 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 normally through all forms of magical darkness up to 100 ft.

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: +11 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 5) piercing damage plus 7 (2d6) necrotic damage. On a successful bite attack, the dragon regains health equal to the necrotic damage dealt, and the target creature must make a DC 20 Constitution saving throw. If it fails, it has disadvantage on all Strength based ability checks and saving throws until the end of its next turn. Also, any attack made using Strength deals half its normal damage.

Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 15 (2d6 + 5) slashing damage.

Tail. Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 17 (2d8 + 5) 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 20 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 20 Constitution saving throw, taking 63 (15d6) 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. A humanoid killed by the dragon's breath weapon becomes an undead shadow and rises from its corpse acting immediately after the dragon in the initiative count. The shadow is under the dragon’s control.

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 can conjure a black mist to surround the area within a 100 foot radius centered on the dragon. A creature with darkvision can’t see through this darkness, and no light, magical or nonmagical, can illuminate it. This effect lasts until the end of the dragon's next turn.

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 10 feet of the dragon must succeed on a DC 19 Dexterity saving throw or take 15 (2d6 + 5) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.