Ancient Deathbringer Dragon

Chill of the Void. Cold damage dealt by the Deathbringer Dragon ignores damage resistance, but not immunity.

Legendary Resistance (4/Day). If the dragon fails a saving throw, it can choose to succeed instead.

Abyssal Voyager. Deathbringer Dragons roam between layers of the Abyss for millennia. They require no food, drink, sleep, nor air to survive.

Collapsing Star. When the Deathbringer Dragon is dealt a killing blow, the star at its core begins to collapse, eventually exploding. Each creature within 1d4 miles of the dying Deathbringer Dragon takes 55 (10d10) magical bludgeoning damage, 55 (10d10) cold damage, and 55 (10d10) psychic damage. This damage can be reduced by half with the following saving throws: DC23 Dexterity saving throw against magical bludgeoning damage, DC23 Constitution saving throw against cold damage, and DC23 Wisdom saving throw against psychic damage. If a player fails more than one of these saving throws, they take the damage, and their soul is bound to a random layer of the abyss, freed only by a Wish spell.

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: +17 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) piercing damage.

Claw. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 17 (2d6 + 10) slashing damage.

Tail. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 19 (2d8 + 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 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.

Breath Weapons (Recharge 5–6). The dragon uses one of the following breath weapons.

Graviturgic Breath. The dragon exhales a 90-foot cube of increased gravity. Any flying creature must succeed a DC23 Strength saving throw or have its flying speed reduced to 0 and crash to the ground, taking 5 (1d10) bludgeoning damage per 10 ft. traveled. Any creature on the ground must succeed a DC23 Strength saving throw or take 17 (5d6) force damage and have its movement reduced to 0. The entire area is considered difficult terrain. The dragon cannot use this breath twice in a row. This field lasts until the breath weapon recharges.

Solar Flare Breath(Recharge 5-6). The dragon exhales raw fire from a collapsing star in a 60-foot cone. Each creature must make a DC23 Dexterity saving throw, taking 35 (10d6) fire damage and 35 (10d6) cold damage on a failed save, or half as much on a success.

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.

Void Slip (Costs 2 Actions). The dragon twists the fabric of reality. Each creature within 20 feet of the dragon must succeed on a DC23 Dexterity saving throw or take 13 (2d6 + 6) bludgeoning damage and be knocked prone. The dragon can then teleport to an unoccupied space within 50 feet.

Obelisk Strike (Costs 4 Actions). The dragon wrenches 5 (2d4) Obelisks out of the Abyss. Starting from the furthest living creature within 150 feet of the dragon, roll 1d6 to determine if they are hit with an Obelisk, subtracting from the total rolled Obelisks until all are landed. On an odd number, the creature is struck with an Obelisk dealing 33 (6d10) magical bludgeoning damage, and on an even number the Obelisk lands within 10 ft. and becomes a permanent 20 ft. tall pillar. This ability can only be used once per day.