Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.
Undead Fortitude (3/Day). If the dragon would be brought to 0 HP by any damage besides radiant damage or damage from a critical hit, it makes a Constitution save (DC 5+the damage taken) and on a success, it is instead reduced to 1 HP.
Necrotic Aura. At the beginning of each of the dragon's turns, all creatures within 30 feet of the dragon must make a Constitution saving throw (DC 18) or take 7 (2d6) necrotic damage.
Necromantic Mastery. The dragon can cast the following spells as an action:
- 3/day: Create Undead (6th level)
- 2/day: Create Undead (7th level)
- 1/day: Create Undead (8th level), Create Undead (9th level)
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: +14 to hit, reach 10 ft., one target. Hit: 21 (2d10 + 10) piercing damage plus 7 (2d6) fire or necrotic damage, dragon's choice.
Claw. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 17 (2d6 + 10) slashing damage.
Tail. Melee Weapon Attack: +14 to hit, reach 15 ft., all creatures in a 15 foot cone. Hit: 15 (1d8 + 10) 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 19 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.
Fire Breath (Recharge 5–6). The dragon exhales fire in a 60-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 70 (20d6) fire damage on a failed save, or half as much damage on a successful one.
Siphon Life (1/Day). The dragon emits a wave of purple and black negative energy. All living creatures within 60 feet of the dragon take 32 (9d6) necrotic damage (Dexterity save DC 21 halves), and the dragon heals for the amount of damage dealt to other creatures.
The dragon can take 4 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 22 Dexterity saving throw or take 15 (2d6 + 8) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.
Siphon Life (Costs 3 Actions). The dragon performs its Siphon Life attack, if it has not done so already for the day.
Description
The odor of sulfur and pumice surrounds a red dragon, whose swept-back horns and spinal frill define its silhouette. Its beaked snout vents smoke at all times, and its eyes dance with flame when it is angry. Its skeletal form and rotting flesh betrays its lack of traditional nourishment, and the intense dark energies surrounding it indicate that it does not suffer from the lack of food, instead subsisting off of dark magic.
Lair and Lair Actions
On initiative roll 20 (losing ties), the dragon can take one of the following actions but cannot perform the same action twice in a row.
Vivisect. A hole opens up in the darkness beneath one living creature in the lair. The creature falls in and is embedded in the ground from the waist down. A Dexterity saving throw (DC 15) negates the trapping, and an Athletics check (DC 15) will allow the creature to escape. While trapped in the ground, the creature is considered helpless. They take 14 (4d6) necrotic and 14 (4d6) slashing damage per round until freed.
Dark Ward. A contiguous area no greater than 50 square feet becomes difficult terrain and all creatures ending their turns in the area take 3 (1d6) necrotic damage. This terrain returns to normal when the next lair action is taken.
Vile Plume. A circular area (10 ft diameter) in the lair is filled with purple smoke. This purple smoke is a deadly poison and has an immediate effect of dealing 36 (12d6) damage and causing those in contact with it to be poisoned if they do not succeed on a Constitution saving throw (DC 18). It also grants concealment to creatures inside it. The Vile Plume lasts until the next lair action is taken.
Dark Sight. The dragon gains advantage on attack rolls until its next lair action is taken. This ability does not provide advantage on attack rolls made against creatures illuminated by bright magical lights.
Black Hole Revelation. A sphere appears in one corner of the lair and pulls all living creatures 15 feet towards it. Contacting the sphere results in taking 28 (8d6) damage and reveals a weakness of the creature that contacted the sphere, making the dragon's next attack against them an automatic critical threat.