As a Fighter taking the Ashen Warrior subclass, you are able to enhance your abilities and attacks using Flaming Arts.

Ashen Marks

Starting at 3rd level, the fighter gains 3 Ashen Marks, allowing for the use of Searing Arts in combat. Expended Marks can only be regained after a Long Rest or after using Remembrance of Life. The fighter is granted 1 more Mark for each level of Fighter taken, capping at 20.

Searing Arts

Beginning at 3rd level, you have become a novice wielder of Ash, allowing you to pick two Searing Arts and more at later levels. These can apply special effects meant to aid the warrior in battle, either beneficial to themselves or harmful against their targets. Some Searing Arts require saving throws from the target of the attack.

Searing Art save dc = 8 + your proficiency bonus + your Dexterity modifier

Blinding Blade

As a bonus action, you can imbue your weapon with dark energy, consuming an Two Mark. On your next attack, the target must succeed on a Dexterity saving throw or become Blinded until the end of their next turn. Attacks on a blinded target are made with advantage and all attacks made by the target are rolled with disadvantage and any ability checks requiring sight automatically fail. 

Flare

As a reaction, when an enemy makes a melee attack on an ally within 30 feet of you, consume 3 Marks to impose Disadvantage on one attack. You must have line of sight on the enemy attacking.

Momentum Strike

As a bonus action, when consuming a Mark for Momentum Strike, choose 1 attack from an action to apply the effect to. As you attack, you gather more momentum, which allow greater effects to occur. Doing so consumes more Marks. Think of it as a combo move.

Applying this to the 1st attack consumes one Mark and pushes the target back 15 feet. On a failed Dexterity save they are knocked prone. Applying it to the 2nd consecutive attack consumes two Marks and sends the target back 20 feet. On a failed Strength saving throw, the target is Disarmed and the weapon is dropped in the space in front of you. Applying this to the 3rd consecutive attack on an action, the force is so immense that they are driven into the ground, dealing an additional 1d10 force damage and becoming Restrained. 

Missing any one of the attacks before or the effected attack itself still consumes the Marks.

Obsidian Armor

As a bonus action, consume two Marks and increase your AC by 2. Lasts until damage is taken or the beginning of your next turn.

Scorching Slash

As a Bonus Action, you can consume a Mark and add 1d4 Fire Damage to your next Attack. If the attack misses, the magic is dispelled.

Remembrance Of Life

Spend 10 minutes to dissolve the body of a creature Medium or bigger and regain Ashen Marks equal to your half your Fighter level rounded down. You must take a Long Rest before using this trait again. 

Igneous Edge

At 7th level, you can spend an hour to attune to a weapon you are proficient with. Attacks with your attuned weapon are considered magical.

Carbon Body

At 10th level, you become resistant to Fire Damage. Your resolve makes it harder to become Petrified, giving you Advantage on saving throws against the condition.

Your body is also now able to absorb Fire Damage and heal from certain attacks against you. You can use your reaction to heal all fire damage taken from one attack. You can use this a number of times equal to your Strength modifier. Charges are regained after a Long Rest.

 

Wings Of The Ashen

At level 15, as an Action, consume Marks equal to half your Fighter level to grow wings. For 1 hour or until dismissed, gain flight speed equal to your walking speed. This feat can only be used once and requires a Long Rest between uses.

Beacon Of The Infernal

At 18th level, as an action, you become a beacon of bright light and flame, strengthening the resolve of those around you. For 1 minute, you are considered a source of Daylight, dispelling both natural and magical darkness in a 60-foot-radius sphere. Any creatures considered friendly within 30 feet of you gain advantage on attacks and regain 1d6 Hit points each round, as long as they stay within 30 feet of you.