You have dedicated your training to fighting enemies in one on one combat, honing your skills to favor letting the fate of battle being decided in a single blow rather than a long period of fighting. Through a focused mind and sheer willpower you can crush through a foe's defense and deal a devastating strike.

Glorious Clash

At 3rd level you can challenge enemies to a martial clash in the midst of battle. When you take the Attack action you can make a contested melee attack roll with an opponent in melee range. The opponent must be wielding a weapon or have a natural weapon, such as a red dragon's bite attack. If you win the contested attack roll the target takes damage equal to the number they lost by plus your fighter level, with the damage type being the damage of the attack used.

Once you lose a glorious clash you cannot clash again until you finish a short or long rest, or if you use a bonus action to expend a hit die to regain glorious clash. 

When you gain the extra attack feature you can repeat this special attack roll an additional time(s) equal to your additional attacks as part of the same action. This can target the same creature or a different creature within melee range with the same criteria. 

This feature also cannot be used on a creature that is incapacitated or otherwise unable to take actions. 

Trained Duelist

Also at 3rd level, whenever you would finish a short rest you can regain a number of hit dice equal to half your proficiency bonus (rounded down). Once you regain hit dice this way you cannot do so again until you finish a long rest. You only regain these hit dice at the end of the short rest.

Grit

Starting at 7th level, whenever you would fail an Intelligence, Wisdom, or Charisma saving throw you can use your reaction to add your Constitution modifier to the roll, potentially turning it into a success. You can use this feature a number of times equal to your Proficiency bonus. Once you expend all uses of this feature you cannot use it again until you finish a long rest, or if you use a bonus action to expend two hit dice to regain one use of this feature. 

Counter Clash

Starting at 10th level you have honed your skills far enough to intercept incoming blows. Whenever you would be hit by a melee weapon attack or melee spell attack you can use your reaction to turn this attack into a glorious clash, turning it into a contested attack roll and following the rules of glorious clash (except for the rule of the opponent needing to be wielding a weapon if the attack is a melee spell attack). If you would win this clash you turn the opponent's hit into a miss and deal the normal damage for winning a glorious clash. 

You can use this feature a number of times equal to your proficiency bonus. Once you expend all uses you cannot use it again until you finish a long rest, or if you use a bonus action to expend two hit dice to regain one use of this feature. 

Peerless Accuracy

Starting at 15th level, whenever you would fail a Glorious Clash you can instead treat the result as if you beat your opponents roll by 1. Once you use this feature you cannot use it again until you finish a short rest. 

Grand Clash

Starting at 18th level, whenever you would initiate a glorious clash with a creature you can give yourself advantage on the attack roll and add double your proficiency bonus to the attack roll. If you would win this clash by 5 or more you also deal an additional 10d6 damage, the damage type being the damage type of your weapon. 

Once you enhance a glorious clash in this way you cannot do so again until you finish a long rest.