Dune Dancer Fighter

You learned to dance before the blade.
The shifting sands upon you stepped created difficult terrain for such elegant dances that you preformed.
These patterns and physiques learned from the dance translated well into that of the sword, particularly that of the two swords. 

Dual Dancer

At 3rd level,

Gain Proficiency in Performance.

While wielding two melee weapons you gain a +1 to your AC. 
When Dual Wielding, one of your weapons does not need to have the light tag, though they cannot be heavy. 

Additionally, you can use your second wind in a different way than normal.
As a bonus action you may use a charge of second wind to instead gain hit points equal to a 1d4 + half your fighter level (rounded down). Then as part of that bonus action you gain an additional 15ft of movement and you do not provoke opportunity attacks and may make one attack with your off hand weapon. 

Once you gain this feature you cannot benefit from the feat "Dual Wielder"

Captivating Combat

Starting at 7th level, when you attack a creature with a melee weapon attack from both you main hand and off hand, whether you hit or miss, you can force the creature to make a charisma saving throw (DC = 8 + your performance modifier). On a failed save it is charmed in such a way that it cannot use its action on its next turn. 

Once a creature succeeds on a save against this feature it is immune to this feature for 24 hours. 

Whirlwind Dance

At 10th Level,
While dual wielding you gain the ability to wield two non light weapons. 

You can now use an action to to begin spinning with both weapons you are holding, similar to that of a whirlwind. 
While in this whirlwind state you do not provoke opportunity attacks. You may make one attack against every creature you move towards, within 5ft of your position. You may only attack each creature once on this turn. 

At the end of your turn you stop spinning and need to make a constitution saving throw, DC 15. 
On a failed save you gain a level of exhaustion that is removed from a short rest. 
On a successful save your move speed is reduced by half until the end of your next turn. 

Faster Pace

At 15th level,
When you use your bonus action to make an offhand attack, you can make an additional attack with your offhand weapon as part of that bonus action. This additional attack benefits from all the same benefits your original bonus action attack would. 

Persevering Dancer

At 18th level, when you use your action surge, you also gain an additional bonus action. 

In addition, their are no limitations on what weapons you can use for dual wielding. This includes ignoring the two handed tag.