Ember Knight

An ember knight employs martial techniques combined with potent fire magic. While ember knights are often mistaken for the more common eldritch knights at first glance, the source of an ember knight’s magic comes from within, rather than from the study of magic. In this way they are comparable to sorcerers. While the potential to become an ember knight might be within someone from birth, this potential typically doesn’t manifest until that person has a few battles under their belt. This event is generally referred to as an ember knight’s “kindling,” where they first begin to wield their fiery powers.
Once an ember knight “kindles,” their skills become a desired commodity. Their presence can inspire fear in their opponents, and awe in their onlookers, as their fiery weapons and arrays of burning embers sow death and destruction. Many become mercenaries, or even leaders of mercenary groups, and their services are often highly sought after. Anyone that employs an ember knight finds them to be worth their price.

(Class taken from "Blazing Dawn Player's Companion". All I have done is add it into D&D Beyond)

Flameborn

Starting at 3rd level, you can use a bonus action to imbue fire magic into a weapon you wield. Until the weapon leaves your possession or you end this feature using another bonus action, the weapon’s damage type becomes fire damage and it sheds bright light in a 10-foot radius and dim light 10 feet beyond that.

Also, you gain darkvision out to a range of 60 feet. If you already have darkvision, its range instead increases by 60 feet.
Your darkvision is unusual: everything you see in darkness is in a shade of red.

Ember Magic

Also at 3rd level, you can use a bonus action to allow fiery power to swell within you. When you activate this feature, and at the start of each of your turns for the next minute, you roll a d8. This die increases to a d10 at 10th level and a d12 at 18th level. You conjure a number of embers equal to the number rolled. These embers float around you until they are spent or until they vanish at the start of your next turn You have two uses of this feature, and you regain all expended uses of it when you finish a long rest. You gain an additional use at 7th level and one more at 15th level.
The embers conjured by this feature can be spent to fuel the following abilities:
Ember Strike: When you hit a creature with an attack, you can cause any number of your conjured embers to fly at the attack’s target. The target takes 1 fire damage for each ember you spend.
Propelling Blasts: On your turn, you can spend any number of your conjured embers to propel yourself with blasts of fire (no action required). You can fly up to 5 feet for every ember spent.
Smoke Pillars: On your turn, you can spend any number of your conjured embers to create pillars of smoke (no action required). For each ember spent, you create a cloud of thick smoke that fills a 5-foot diameter, 10 foot high cylinder centred on a point you can see within 30 feet of you. The smoke heavily obscures its area, and lasts until the start of your next turn

At 18th Level, the minimum number of Embers summoned equals your Constitution modifier: {{modifier:con}}

Swift Spark

At 7th level, the fire within you energizes your spirit. Your speed increases by 10 feet, and you gain proficiency in Dexterity saving throws. If you already have this proficiency, you instead gain proficiency in another saving throw of your choice.

Improved Ember Magic

At 10th level, the three abilities associated with your Ember Magic feature improve as follows:
Ember Strike. You can cause another creature of your choice within 5 feet of the target to also take 1 fire damage for every ember spent.
Propelling Blasts. This flight doesn’t provoke opportunity attacks.
Smoke Pillars. In the radius of your darkvision, you can see through the smoke pillars as if they were only lightly obscured.

Fiery Surge

Starting at 15th level, your Action Surge becomes imbued with fire magic. When you use your Action Surge, your speed increases by 10 feet until the end of the turn. While this speed increase lasts, your movement doesn’t provoke opportunity attacks, and you can choose to leave behind a trail of fire where you step. The trail is 5 feet wide, follows your movement, and lasts until the start of your next turn. A creature other than you that enters the trail for the first time on a turn or ends its turn there takes fire damage equal to your fighter level.

Pyromancer Adept

At 18th level, you gain resistance to fire damage, and the minimum number of embers you can gain on a turn from your Ember Magic feature equals your Constitution modifier.