b'Dragon, Vile \n'b'  Huge   dragon ,  chaotic evil  \n'b'  Armor Class  20 (natural armor)  Hit Points  589 (38d20+190)  Speed  60 ft., burrow 50 ft., fly 100 ft. (hover)\n'b' STATS STR: 23 (+6) DEX:  20 (+5)  CON:  21 (+5)  INT:  19 (+4)  WIS:  8 (-1)  CHA:  24 (+7)  \n'b'\n'b'\n'b'\n'b'\n'b'\n'b'\n'b'  Saving Throws   Wis  +7  Skills   Deception  +15,  Perception  +15,  Stealth  +13  Damage Resistances  acid, radiant, thunder  Damage Immunities  necrotic, poison  Condition Immunities   charmed ,  frightened ,  poisoned   Senses  blindsight 120 ft.,  darkvision  600 ft., passive  Perception  25  Languages  Common, Deep Speech, Draconic  Challenge  28 (120,000 XP) \n'b' SPECIAL TRAITS \n'b'\n'b'  Dark Sight . Magical  darkness  doesn\xe2\x80\x99t impede the dragon\xe2\x80\x99s  darkvision . \n'b'  Legendary Resistance (3/Day) . If the dragon fails a saving throw, it can choose to succeed instead. \n'b'  Midnight Aura . While the dragon is conscious, light levels in a 90-foot radius around it are reduced by one step (bright light becomes dim light, dim light becomes darkness). Only daylight and other magic can negate the dragon\xe2\x80\x99s midnight aura. \n'b'\n'b' ACTIONS \n'b'\n'b'  Multiattack . The dragon can use its Frightful Presence. It then makes four attacks: one with its bite, one with its tail, and two with its claws. \n'b'  Bite .  Melee Weapon Attack : +14 to hit, reach 20 ft., one target.  Hit : 32 (4d12+6) piercing damage plus 32 (5d12) necrotic damage. If the target is a creature, its hit point maximum is reduced by an amount equal to the necrotic damage taken. The target dies if this attack reduces its hit point maximum to 0. The reduction lasts until removed by the  greater restoration  spell or other magic. \n'b'  Claws .  Melee Weapon Attack : +14 to hit, reach 150 ft., one target.  Hit : 19 (2d12+6) slashing damage. \n'b'  Tail .  Melee Weapon Attack : +14 to hit, reach 20 ft., one target.  Hit : 19 (2d12+6) bludgeoning damage plus 39 (6d12) poison damage, and the target must make a DC 22  Constitution  saving throw. On a failed save, the target is  poisoned  for 1 minute or until the poison damage is healed. \n'b'  Breath Weapons (Recharge 5-6) . The dragon uses one of the following breath weapons.\n'b'\n'b'\n'b'  Maddening Breath . The dragon exhales pure madness in a 90-foot cone. Each creature in the area must make a DC 22  Wisdom  saving throw or gain a short-term madness for 1 minute. If the saving throw fails by 5 or more, the creature gains a long-term madness for its normal duration, and if failed by 10 or more the creature also gains an indefinite madness. A creature can use a bonus action to repeat the saving throw, ending the short-term madness on a success. \n'b'  Necrotic Breath . The dragon exhales unholy energy in a 120-foot line that is 10 feet wide. Each creature in the area must make a DC 22  Charisma  saving throw, taking 72 (16d8) necrotic damage on a failed save, or half as much damage on a successful one. \n'b'\n'b'  Change Shape . The dragon magically polymorphs into a beast that has a challenge rating no higher than its own, or back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (the dragon\xe2\x80\x99s choice). In a new form, the dragon retains its alignment,  hit points , hit dice, ability to speak, proficiencies, legendary  resistance , lair  actions , and  Intelligence ,  Wisdom , and  Charisma  scores, as well as this action. Its statistics and capabilities are otherwise replaced by those of the new form, except any class features or legendary actions of that form. \n'b'  Frightful Presence . Each creature of the dragon\xe2\x80\x99s choice that is within 120 feet of the dragon and aware of it must succeed on a DC 22  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\xe2\x80\x99s saving throw is successful or the effect ends for it, the creature is immune to the dragon\xe2\x80\x99s frightful presence for the next 24 hours. \n'b'\n'b' LEGENDARY ACTIONS \n'b' 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\xe2\x80\x99s turn. The dragon regains spent legendary actions at the start of its turn. \n'b'\n'b'  Divine Sense . The dragon detects the presence of celestials, fiends, and undead within 120 feet. This functions as the herald class feature except that the dragon also notices any creature of evil alignment within range that fails a DC 22  Wisdom  saving throw. \n'b'  Tail Attack . The dragon makes a tail  attack . \n'b'  Wing Attack (Costs 2 Actions) . The dragon beats its wings. Each creature within 15 feet of the dragon must succeed on a DC 22  Dexterity  saving throw or take 17 (2d12+6) force damage and be forced\xc2\xa0 prone . The dragon can then fly up to half its flying speed. \n'b'\n'b' ABOUT \n'b' All creatures can be tempted by power-dragons perhaps most of all. Unlike soulhoarders these unnatural monsters have all known a life from before their transformations into things of darkness. They were however ultimately deceived (whether by artifact, ritual, or mortal trickery) and in exchange for their souls and their wits they have been granted wicked strength. It is an easier thing than one might think to fool a vile dragon yet only a fool with a deathwish willingly agrees to anything with a creature so prone to deception. \n'b' The goals of a vile dragon are foul and intricate but ultimately quite basic, lacking the nuance of schemes by wiser wyrms. They prefer to slay other dragons and take over their lairs, known to keep courts of sycophants and undisciplined cults (eating any who fail to pledge fealty and excited by the taste of \xe2\x80\x9cgoodness\xe2\x80\x9d). Almost tragically these creatures\xe2\x80\x99 penchants for power are never sated even after they\xe2\x80\x99ve mutated, and a vile dragon is compelled to seek out more through artifacts and magic still without heed for the full consequences of their actions.'