Oath of the Dragonslayers

Founded long in the Ancient Past, such that those who first set the core tenets into stone into caves long forgotten by time are now not even dust, this order of defenders seeks to protect innocents from the dangers posed by Dragons. Maybe it was founded by a small Orc tribe being hunted for sport by a Great Red Dragon, or maybe it was an early human city that sought out defenders in a time of need when they were being assailed by a Black Death... that is the long past, and long forgotten. Nowadays with the rampant Dragon fanaticism, this order works in the shadow, in secret to continue their work unabated of protecting the innocent that must be protected from a Dragon who seeks to harm them, or punishing those Dragons who step out of line.

The Oath of the Dragonslayers is a solemn commitment to punish those Dragons who stray from goodness and abuse their power. When a village is slaughtered or burned to the ground by dragon fire. When a dragon rampages through the countryside. When A King's ransom is stolen by a greedy Dragon — at times like these, these slayers arise to reap bloody vengeance on the Dragon, right their wrongs and protect the people they've harmed.

TENETS OF THE DRAGONSLAYERS

The tenets of the Oath of the Dragonslayers is set in stone and codified for those who seek to combat these ancient foes. They seek to right the wrongs set by these overgrown, flying lizards. They seek to eradicate those that pose a threat, that stray out of line and bring harm to the innocent. Those who choose to follow the ancient Oath of the Dragonslayers, and join the order usually are of a lawful good or lawful neutral alignment. 

One enemy. Dragons who seek out evil must be punished, as must all who follow them.

By Any Means Necessary. My enemies will not shy away from whatever it takes to win, I shouldn't either.

Resolution. I must be absolutely unwavering and undeterred in pursuit of my goals.

Vigilance. The threats you face are cunning, powerful, and subversive. You must always be on your guard.

Channel Divinity

When you take this oath at 3rd level, you gain the following two Channel Divinity options.

Slayer's Venom. As a bonus action, using your Channel Divinity, you can magically coat your weapon in a special poison refined in secret over centuries by previous Paladins of the Oath of the Dragonslayers. The poison lasts for one hour.

The first time you hit any enemy that does not have the Dragon type with an attack roll using the poisoned weapon, the enemy must succeed on a constitution saving throw or become poisoned for one minute. At the end of each of the poisoned creature's turn, it can make a constitution saving throw, ending the effect on itself on a success.

The first time you hit an enemy of the Dragon type with an attack roll using the poisoned weapon, the enemy must succeed on a constitution saving throw, or become poisoned for one minute. An enemy of the Dragon type has disadvantage on this saving throw, and on a failure it takes an amount of poison damage as well, which ignores resistance and immunity to poison damage. The amount of poison damage it takes on a failed save scales with your Paladin level. It starts at 2d6 at 3rd level, increasing to 3d6 at 5th level, 4d6 at 9th level, 5d6 at 13th level, and 6d6 at 17th level. At the end of the poisoned creature's turn, it can make a constitution saving throw at disadvantage, ending the effect on itself on a success.

(On subsequent failed saves against this effect while poisoned by this effect, a creature will not take additional poison damage. The additional poison damage is only on a failure against the initial save, not subsequent saves)

Dragon's Bane. Using magic that mimics the tools of your enemy, you can turn the fear many Dragon's exude back against them. As an action, you present your holy symbol and exert a frightening presence similar to those of Dragons, using your Channel Divinity. Choose one creature within 60 feet of you that you can see. That creature must make a Wisdom saving throw, unless it is immune to being Frightened. On a failed save, the creature is Frightened of you until the end of your next turn. Any creature Frightened by this effect can't take reactions while they're Frightened by this effect and any flying speed they have is reduced to 0 for the duration.

If that creature is a Dragon, it has disadvantage on the saving throw, and if it fails by 5 or more, it is stunned until the end of your next turn. 

Oath Spells

You gain oath spells at the paladin levels listed.

Oath of The Dragonslayers Spells

Paladin Level	Spells
3rd	absorb elements, hunter’s mark
5th	earthbind, blindness deafness
9th	fly, protection from energy
13th	fire shield, locate creature
17th	hold monster, animate objects

Aura of Resistance

By 7th level, ancient dragon slaying techniques and magicks have formed a resistive shell of magic which protects you and those near you from harm. 
You and friendly creatures within 10 feet of you have advantage on saving throws against any effect which deals fire, cold, lightning, acid or poison damage on a failed saving throw.

In addition, for Breath Weapons of creatures of the Dragon type, you and friendly creatures within 10 feet of you take no damage on a successful save if you would normally take half damage on a successful save.

At 18th level, the range of both effects of this aura each increase to 30 feet.

Dragon Scales

Starting at 15th level, in order to fight Dragons, the greatest natural creature that evolution has ever produced, you must acclimate yourself not only to their deadly breath, but also their claws which are sharper than any longsword, and their teeth, which are longer than any spear. You have hardened your heart to the fear of Dragons, and your body has followed suit, developing a version of the hide sported by most Dragons, acting as another layer of defense. The paladin gains resistance to bludgeoning, piercing, and slashing damage from nonmagical weapons, unarmed strikes and natural weapons. 

Dragon Slayer

At 20th level, for one minute, you appear as an avatar of Dragon Slaying. Overtop of your person, a translucent set of armor forms around you, with ethereal dragon bone jutting from various parts of it. A glowing aura appears around your weapon, looking like a vicious, ethereal greatsword of flame with hooks and barbs meant for ripping and tearing flesh, bone and scale alike. Lastly, a helmet of the same ethereal quality as the rest of your avatar forms over your head, looking like the Maw of a Dragon with inset teeth ringing the hole for your eyes.

• Your walking speed increases by thirty feet.
• You have advantage on attack rolls against Dragons.
• When you hit with an attack roll and deal damage, you deal an additional 1d8 force damage, or if the creature you hit is a Dragon, you deal an additional 3d8 poison damage instead, ignoring resistance and  immunity to poison damage.
• Your melee weapon attacks score a critical hit on a roll of 19 or 20 on the d20

Once you use this feature, you can’t use it again until you finish a long rest.