Cuvulkonikbuz the Crown-Scourge

Inspired by the Inferno of the Star Mounts. Meant for extremely high powered parties.

CR: 40

A great wyrm of immense size and legacy, Cuvulkonikbuz goes by many names in many places, such as 'scarcer of heaven', 'Storm-Incarnate', 'The Lightning before the Thunder' or what he is most known as is in the material plane, 'The Crown-scourge'. He is a insidious wyrm concerned about legacy more than anything and due to such obsession, he seeks out strong foes for hard fought victories in very public settings for onlookers to craft his legend further. He is a master in all things lightning and thunderous, even focusing his magics to further the strength of his lightning prowess, he further studies and tries to invent new magics relating to lightning and thunder. Additionally, he is very much so theatrical and has a hands on approach to his own matters, The Crown-scourge has little need to have lackeys although he is known for manipulation from time to time. He has an enslaved Dijinni named Stratus who is bound by a magical ring Cuvulkonikbuz wears, the Dijinni was a good natured although Naive woman who got deceived by the blue wyrm, whenever the Crown-scourge wishes to communicate with someone, he either uses a spell or sends the Dijinni to speak while being scried upon.

He is not known to have any off-spring but little is known of such a dragon aside from his violent and theatrical nature.

Appearance. He is a massive dragon whom's size eclipses that even of an ancient dragon, his horn on the head that is usually seen on other blue dragons has been snapped off and his scales and body are covered in scars from countless battles that he has survived and thrived from. The colour of his scales as well isn't the usual vibrant blue colours often seen in his kin, the Crown-scourge has a Indigo blue colour, given him a more subtle and faded look which assists in helping him blend into a cloudy sky.

Personality. His personality is that of self-indulgent Narcissism. He will never fully cull a population or allow for someone to for then there will be no one to sing the tales of his glory. Although he enjoys the praise and fear of the weak masses... he isn't at all easily deceived. However, he actually tends to be the deceiver, beguiling or maybe threatening people to do his bidding. Regardless, when it comes to his fights, the flashier the better, there has been times where he left purposeful and obvious clues or even call-out cards for fights to build anticipation. 

Hoard. A hoard of a Great Wyrm is vast and not bound to a single hoard. Across all his hoards, the total value would be 3 million gold pieces. 1.5 million in coins, 1 million in gems and 500,000 in works of art. There are additionally magic items of all sorts in his hoard however the most notable item in one of his hoards is a legendary item called the Blue Dragon Mask (Source is from Tyranny of Dragons). Additionally, he has a 'healing hoard' as he calls it where he has a ring of regeneration and periapt of wound closure as well as being stocked with all manner of healing potions. The Dijinni Stratus knows where each hoard location is as she has been to all of them.

The Crown-scourge resides within the Northlander and Moonshae Isles of Faerun, his hunting grounds being Korinn Archipelago, The Whale bones, Ruathym, Alaron, Norland, Moray, Snowdown and Gwynneth. He has numerous hoards throughout this area and some outside these islands on mainland Faerun, however, his main hoard resides in the furthest south island of Ruathym.

Thunderstorms rage around the legendary blue dragon’s lair, and narrow tunnels are carved whole throughout the area, leading to dead ends, pits and easily collapsible tunnels which can crush, restrain or suffocate nosy adventurers.

Lair Actions

On initiative count 20 (losing initiative ties), the dragon takes a lair action to cause one of the following effects; the dragon can’t use the same effect two rounds in a row:

• Part of the ceiling collapses above one creature that the dragon can see within 120 feet of it. The creature must succeed on a DC 18 Dexterity saving throw or take 13 (4d6) bludgeoning damage and be knocked prone and buried. The buried target is restrained and unable to breathe or stand up. A creature can take an action to make a DC 12 Strength check, ending the buried state on a success.
• A cloud of sand swirls about in a 30-foot-radius sphere centered on a point the dragon can see within 120 feet of it. The cloud spreads around corners. Each creature in the cloud must succeed on a DC 18 Constitution saving throw or be blinded 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.
• Lightning arcs, forming a 5-foot-wide line between two of the lair’s solid surfaces that the dragon can see. They must be within 120 feet of the dragon and 120 feet of each other. Each creature in that line must succeed on a DC 18 Dexterity saving throw or take 13 (4d6) lightning damage. 
• The ground tremors and ruptures with a thunderous blast of a 20-foot-radius sphere that the dragon can see within 120 feet of it. Each creature in that sphere must succeed on a DC 18 Dexterity saving throw or take 13 (4d6) thunder damage and be knocked prone. 

Regional Effects

The region containing a legendary blue dragon’s lair is warped by the dragon’s magic, which creates one or more of the following effects:

• Thunderstorms rage within 10 miles of the lair.
• Dust devils scour the land within 10 miles of the lair. A dust devil has the statistics of an air elemental, but it can’t fly, has a speed of 60 feet, and has an Intelligence and Charisma of 1 (−5).
• Surges of potent magic emanates in the general area, almost suffocating and heavy with dread for those who notice it, when an arcana check is performed by a magic caster in the area, they must make a DC 20 Constitution saving throw or they vomit. If they used detect magic in the area, they must make a DC 20 check with their spell modifier, if they succeed, the spell performs as normal, if they fail, the spell ends and the caster vomits.
• These harsh conditions has made the area devoid of civilised life and very few animals are present.

If the dragon dies, the dust devils disappear immediately, and the thunderstorms and residue magic abate within 1d20 days. if the roll is 20, the thunderstorms and residue magic stay perpetually instead.