The Ancient Blue Dragon

An Ancient Blue Dragon is one of the most ancient, powerful, and vainglorious mortal beings in all of Toril.  By the time a Blue Dragon reaches the Great Wyrm status of its life, it has immense sorcerous power and unparalleled flight.  No other Dragon is more capable and deadly in the air than an Ancient Blue Dragon.  Unlike most of the other Chromatic Dragons, Blue Dragons were not necessarily cruel or malevolent.  They were extremely vain and extraordinarily territorial, but Blue Dragons also had strong familial and community bonds.  Ancient Blue Dragons are often the leaders of Draconic communities.  These creatures are known as a Suzerain.  They adjudicate territorial conflicts, mating disputes, and other societal issues with several younger Blue Dragons.  A Suzerain had influence over sometimes more than two dozen Blue Dragons within a colossal area.

Blue Dragons occasionally employed the services of cunning humanoids like bards, thieves, or assassins to complete missions beyond their territories, or used corrupt politicians, judges, and priests to gain influence over nearby cities. These agents were rewarded handsomely.  Some Blue Dragons even head up Thieves Guilds in desert cities, controlling the illegal activity from their desert lairs.  Especially faithful agents can even be granted a portion of the Blue Dragon's power. These agents are empowered with a portion of the Blue Dragon's innate magical abilities, rewarding them with the abilities of a Warlock in exchange for helping the Blue Dragon enrich its hoard, avenge insults, and manage their criminal empires.  Many have a permanent Teleportation Circle in their lairs to allow their servants to get quickly to and from their lairs without having to cross the treacherous desert sands.  A Blue Draconic Pact Warlock can be handsomely rewarded for faithfully serving their Draconic master, gaining wealth and power.  However, a Blue Dragon will not tolerate any insult to its majestic radiance, no matter how small, so they must be cautious to always be respectful and fawning to their Blue Dragon master.  One poorly worded phrase could see you fried to a crisp.

Blue Dragons are extremely territorial and will often attack without provocation those that invade its borders.  The use their abilities to manipulate the sands and create false terrain to create deadly pitfalls throughout their territory, but even an exceptional flyer like a Blue Dragon cannot be everywhere in their massive territories at once, so they employ Warlocks to watch their borders.  As they share the same kind of territory with Brass Dragons, Blue Dragons often find themselves in conflict with these particular creatures.

The alignment of Warlocks that make a Pact with a Blue Great Wyrm can actually vary a fair bit.  Few that serve a Blue Dragon could be considered good, but a fair few could definitely be considered neutral.  From thieves to judges, from bards to nobles, most servants of a Blue Dragon are lawful neutral, neutral, chaotic neutral, or lawful evil.  Cruel or psychopathic servants are often considered inefficient tools to a Blue Dragon, and they will be cast off.  Some Blue Dragons even overcome the fell influence of Tiamat and become benevolent lords of desert cities, though this is fairly rare.

Some Warlocks that draw their power from a Chromatic Dragon secretly work to subvert and eventually destroy their masters.  Great Wyrms are some of the most powerful creatures on the Material Plane, but they are still mortal, and therefore they can be killed.  However, a Warlock that kills its Draconic patron will lose their magical ability, so many will prepare an Imprisonment spell to trap their Patron's soul to keep their magical powers.

The magic learned from these arrogant creatures focuses on enhancing your roguish skills, manipulating the beasts, winds, sands, and even waters of the desert, unleashing lances of electricity, and teleporting around the battlefield and directly back to their master's lair.

Expanded Spell List

The Ancient Blue Dragon lets you choose from an expanded list of spells when you learn a warlock spell.  You also gain the Mold Earth cantrip.  It does not count against the total number of cantrips you know. The following spells are added to the warlock spell list for you.  Additionally, you learn to speak, read, and write Draconic.

Ancient Blue Dragon Expanded Spells

The Sands of the Desert

Beginning at 6th level, you have spent a great deal of time trekking across the vast desert territories of your Draconic patron; you have become adapted to the hot, arid climates where your patron dwells, and do not suffer the effects of extreme heat as described in Chapter 5 of the Dungeon Master's Guide.  Your patron has also imparted a portion of its innate immunity to electricity unto you, giving you resistance to lightning damage.

Hidden Pitfall

The ground around a Blue Dragon's lair is often filled with deadly sinkholes covered with a light coating of sand that gives way when a careless adventurer steps on it, causing them to plummet into a deep pit.  Powerful Blue Dragons learn to simply cover these sinkholes with super realistic illusions that not only look real, but sound and even smell real.

Beginning at 10th level, you learn the spell Hallucinatory Terrain.  It does not count against the total number of Warlock spells you know.  During the ten minute casting time of Hallucinatory Terrain, you can simultaneously use Mold Earth to create up to five sinkholes of a depth of 1d6x10 feet and a width of 5 feet.  After the Hallucinatory Terrain spell has finished casting, the sinkholes are indiscernible from the surrounding terrain.  A creature that steps into a sinkhole must make a DC 15 Dexterity saving throw or fall into the pit, taking falling damage dependent upon the depth.  A creature that succeeds on their saving throw manages to avoid falling into the pit and lands prone in the nearest unoccupied space near the sinkhole.  The pits are very difficult to escape from; the walls are mostly loose sand and earth, giving little purchase for climbing.  If the pit is more than ten feet deep, they cannot escape without help unless they can fly or make a DC 25 Athletics check for every ten feet they climb.  For creatures with an innate climbing speed, the DC is lowered to 15.  A creature must make an Investigation check against your spell save DC to see through the illusion and avoid the sinkholes. 

You have fallen into a fair few of these sinkholes yourself in service to your Draconic master and have learned to land safely.  As a reaction while falling, you can now reduce falling damage by an amount equal to five times your Warlock level.  If you reduce the damage to 0, you do not land prone.

Aerial Combatant

Blue Dragons are extremely patient creatures.  When in combat, they will fly close to a group of adventurers, unleash their lightning breath upon them, and then fly away before they have a chance to retaliate.  It will repeat this over the course of hours or even days, slowly wearing its enemies down until they are too weak to resist, at which point the Blue Dragon finishes them off and consumes them.  Even creatures that can fly have trouble going toe to toe with a Blue Dragon, as their flight abilities are unparalleled among Dragonkind, making them one of the most skillful aerial combatants in all of Toril.

Beginning at 14th level, you have learned to take to the sky through magical means at will and gain a flying speed of 60 feet.  In addition, you can now flit in and out of combat, harrying and harassing your enemies.  When you cast the spell Expeditious Retreat, you no longer need to concentrate to maintain the spell; it automatically lasts the entire ten minute duration.  You can cast this spell without using a spell slot once per short rest.  Additionally, when you Dash while under the effects of Expeditious Retreat, your movement does not provoke opportunity attacks.