Gargantuan dragon(voidling), unaligned

Armor Class: 22 (Natural Armor)

Hit Points: 546 28d20+252

Speed: 40 ft , climb: 40 ft , can hover

STR

30 +10

DEX

10 +0

CON

29 +9

INT

23 +6

WIS

15 +2

CHA

18 +4

Saving Throws: Dex +7, Con +16, Wis +9, Cha +13

Skills: Intimidation +13, Perception +16, Stealth +7

Damage Resistances: Fire, Necrotic

Damage Immunities: Force

Condition Immunities: Charmed, Frightened

Senses: blindsight 60 ft., darkvision 120 ft., passive Perception 26

Languages: Common, Deep Speech, Draconic, telepathy 120ft.

Challenge Rating: 26 (90,000 XP)

Void Dragon by Peter Lin

Actions

Multiattack. The dragon can use its Maddening Presence. It then makes three melee 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 + 7 2d6 fire + 7 2d6 necrotic 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.   Maddening 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 21 Wisdom saving throw or become frightened for 1 minute. While frightened in this way, a target is also disturbed, acting as if under the effects of the confusion spell. 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 Maddening Presence for the next 24 hours.   Dark Flame Breath (Recharge 5-6). The dragon exhales black fire in a 90-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 45 13d6 fire + 45 13d6 necrotic damage on a failed save, or half as much damage on a successful one. Additionally, on a fail, their hit point maximum is reduced by an amount equal to the necrotic damage taken. This reduction lasts until the target finishes a long rest.

Legendary Actions

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.   Psychic Detection. The dragon makes a Wisdom (Perception) check. It has advantage on this ch if it is searching for creatures within 120 feet of it that have an Intelligence score of 4 or higher.   Psychic Distraction. One creature within 30 feet loses the ability to cast spells of 1st level or higher until the start of the dragons next turn.   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 25 Dexterity saving throw or take 17 2d6+10 bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.