Dual Blade Master is a Fighter who has honed the art of wielding two melee weapons simultaneously, utilizing advanced techniques known as Blade Arts. Each Blade Art represents a distinct fighting style that the fighter can adopt to gain advantages in combat.

Level 3: Dual Strikes

When you take the Attack action while wielding two melee weapons that lack of Heavy and Two-Handed properties, you gain the following benefits:

• Dual Strike Attack. You can replace each of your attacks, including any Extra Attacks, with a Dual Strike attack. When you make a Dual Strike attack, combine the damage dice of both weapons into a single attack roll, and use the highest proficiency bonus from either weapon for the attack roll. Apply only one proficiency modifier to the attack roll. This Attack counts as a weapon attack.
  
   
• Weapon Mastery. If both of your weapons have a Mastery property, when you hit with a Dual Strikes attack, you must choose which weapon’s Mastery property applies to the attack. (remove this if using 2014 rules)
  
   
• Swift Strike. If you have the Dual Wielder feat, after you use Dual Strike attack, you can make one extra attack as a Bonus Action with one of your melee weapons that lacks the Heavy and Two-Handed properties. You do not add your Strength or Dexterity modifier to the damage roll for this Bonus Action attack, unless the modifier is negative.

Level 3: Blade Arts

At 3rd level, you gain access to Blade Arts, specialized combat techniques that you can use during battle. At the start of each of your turns when wielding two melee weapon, you can choose one Blade Art to gain its benefits until the start of your next turn. You can only have one Blade Art active at a time.

Wind Blade

Your speed increase by 10 feet. You can replace each of your attacks made as a Bonus Action with a Dual Strikes attack. If you move in a straight line at least 10 feet toward a target before attacking, you gain a +2 bonus to the attack roll.

Thunder Strike

You gain 1d4 bonus damage on all attacks made with Dual Strikes. Once per turn, you can reroll the lowest damage die from one of your attacks and use the new result.

Guardian Blade

When a creature makes a melee attack against you and you aren’t wearing Heavy Armor, you can use your Reaction to add half of your Strength or Dexterity modifier (rounded down) to your AC until the start of your next turn. Your Opportunity Attacks can also be replaced with a Dual Strike attack.

Level 7: Vindictive Strike

At 7th level, you learn new blade arts that focus on eliminating a single target.

Vindictive Strike

As a Bonus Action, you can mark one creature within 60 feet of you for 1 minute. You have advantage on attack rolls against the marked target, and any 19 or 20 you roll on the attack roll is treated as a critical hit. Once per turn, when you hit the marked target, the attack deals an extra 1d6 damage (or 2d6 on a critical hit) of the same type as your weapon’s damage. The mark ends early if you switch to a different Blade Art or mark another creature.

Level 10: Blade Arts Mastery

At 10th level, your mastery of Blade Arts enhances the effects of your chosen arts:

Wind Blade. You can use your Bonus Action to Dash, and make one mele weapon attack as part of that dash.

Thunder Strike. The bonus damage increases to 2d4.

Guardian Blade. You can wear heavy armor to add half of your Strength or Dexterity modifier (rounded down) to your AC until the start of your next turn. When a creature makes an attack against you. When a creature within 5 feet of you misses with a melee attack, you can make a counter-attack using Dual Strikes as a Reaction.

Vindictive Strike. You always have advantage on saving throws against the marked target, and you are immune to the Frightened and Charmed conditions caused by that creature.

Level 15: Tempest Wrath

At 15th level, you learn new Blade Arts to face multiple opponents at once in combat.

Tempest Wrath

As part of your Attack action, if you hit a creature with Dual Strike Attack, you can immediately make another Dual Strike attack against a second creature within 5 feet of the first, provided the second creature is within your reach. You can’t treat second creature as first creature on next attack with Tempest Wrath.

Level 18: Dual Strike Mastery

At 18th level, you have completely mastered dual strike. Now can use proficiency modifier for both of your weapons during damage rolls, when using Blade Arts.