Dervish

Sworddancer

When you take this archetype at 3rd level, you can use your training in spinning meditative dance as a potent weapon in close quarters. You gain a new action, which you can use to make a melee weapon attack against any number of creatures of your choice within your reach, with a separate attack roll for each target. You then spin in place until the start of your next turn. During that time, attack rolls against you made by creatures within your reach have disadvantage. You cannot move while dancing.
At the start of your next turn you can choose to continue spinning, and make a melee weapon attack against all creatures of your choice within your reach again, or end the dance. You must end the dance after 1 minute, and cannot move while dancing. If another force (such as a shove or the thunderwave spell) moves you, your dance ends. You can dance a number of times equal to your Strength modifier + your Dexterity modifier (minimum of 2) You regain all uses at the end of a long rest.

Quick Feet

Beginning at 7th level, your movement speed increases by 10 feet, and you ignore movement penalties from difficult terrain. You gain proficiency in Acrobatics, and in Performance checks that rely on dancing. You can use your Dexterity modifier instead of your Charisma modifier for those Performance checks, as well.

Whirlwind

At 10th level, you can now move without ending your dance, and if an effect forces you to move while dancing your dance doesn't end.
If you move on your turn while sworddancing and are attacked, you can use your reaction to add your attack bonus to your armor class until the end of your turn. If your armor class exceeds the attack roll after adding this bonus, the attack does not hit you.
Finally, at the end of your turn while dancing you can make a melee weapon attack against any number of creatures of your choice within your reach, with a separate attack roll for each target.

The World Turns

Beginning at 15th level, when you roll initiative and have no uses of Sworddancer remaining, you regain one use.

A Thousand Cuts

At 18th level, you can become a whirlwind of death and blades, moving with uncanny speed and power. When you take the Attack action, you can double the number of attacks you make using that action. This doesn't affect the number of attacks you make with your bonus action or with an extra action, such as that granted by the haste spell.
You can't use this feature and your Action Surge feature on the same turn.
Once you use this feature, you can't use it again until you finish a long rest.