Oath of the Pyre — Sagor från Valoris

The eldsvärd — the flame-swords — are Aurexiel's answer to a world that keeps trying to go dark. Where the Sixfold Light sends preachers and wardens, it sends the eldsvärd with fire in their hands: to burn back the rot, to put the risen dead to rest, and to stand in the doorway of any place the shadow has taken and refuse to let it spread further.

An eldsvärd's fire is said to be a piece of Aurexiel's own light, given heat. It warms the faithful and it judges the corrupt, and those who carry it longest come to believe there is nothing the flame cannot cleanse — no wound, no lie, no darkness — if only enough of it is given.

Tenets of the Pyre

Carry the Flame. Be a light that others can find in the dark.
Give the Corrupt to the Fire. Undeath and rot are the flame's enemies.
Warm Before You Burn. Judge, but do not forget mercy.
Spend the Fire, Never Hoard It. The flame is not yours to keep.

The Oath

Paladin Level	Feature
3rd	Oath of the Pyre Spells, Channel Divinity: Sacred Fire
7th	Aura of Embers
15th	Sacred Conflagration
20th	Aspect of the Flame

Oath of the Pyre Spells

Paladin Level	Always-Prepared Spells
3rd	Searing Smite, Burning Hands
5th	Scorching Ray, Flame Blade
9th	Fireball, Crusader's Mantle
13th	Wall of Fire, Fire Shield
17th	Flame Strike, Destructive Wave

Level 3 · Channel Divinity

Sacred Fire

When you take the Attack action, you can expend one use of your Channel Divinity to wreathe one weapon you are holding in Aurexiel's flame. For 10 minutes, or until you use this feature again, the weapon sheds Bright Light in a 20-foot radius (and Dim Light 20 feet beyond), it counts as magical, and each time you hit with it, it deals an extra 1d8 fire damage — or 1d10 against a Fiend or Undead.

The effect ends early if you stop holding the weapon (no action required to end it).

Level 7

Aura of Embers

While your Aura of Protection is active, you and your allies within it have Resistance to fire damage and can't be Frightened. Aurexiel's fire wards off both the cold that kills and the fear that unmakes.

Level 15

Sacred Conflagration

Your fire was never only fire; it is light given heat, and light does not answer to the same laws. Whenever you deal fire damage, you can choose for that damage to be radiant instead.

And it lingers where it should. Once on each of your turns when you deal fire or radiant damage to a creature, it begins to burn with sacred fire: at the start of each of its turns it takes fire damage equal to your Charisma modifier. The creature, or another creature within 5 feet of it, can take an action to smother the flames — but a Fiend or Undead cannot put them out. On them, the sacred fire burns until they are destroyed or one minute passes.

Level 20

Aspect of the Flame

As a Bonus Action, you become a living avatar of Aurexiel's fire for 10 minutes. Once you do so, you can't again until you finish a Long Rest, unless you expend a level 5 spell slot to do so again. When you unleash it, the air around you ignites.

For the duration, you gain all of the following:

Wings of flame. You have a Fly Speed equal to your Speed and can hover.
Corona. Bright light fills a 30-foot Emanation around you (and dim light 30 feet beyond). When an enemy starts its turn in that light, it takes fire damage equal to your Charisma modifier + your Proficiency Bonus. You have Immunity to fire damage and Advantage on saving throws against effects created by Fiends and Undead.
Judgment unleashed. Once on each of your turns, you can cast a Paladin spell that has a casting time of an action as a Bonus Action — loose a Flame Strike and still strike with your blade.
The pyre spreads. When you reduce a creature to 0 hit points with an attack or a spell, fire erupts from it: each enemy within 10 feet of it takes fire damage equal to your Paladin level, or half as much with a successful Dexterity saving throw against your spell save DC.