Fatal Dancer

There is no telling what led you to a specialty such as this, a Dancer who is also a rogue that is! With you using your performance and skills in battle it's almost like you're on stage presenting your art to an audience soon to be dazzled! Other rogues who use this style are extremely rare, though that does bring the element of surprise nobody expects someone to sail so smooth through the battlefield. Every player views their dancer as their own, whether it be they move through battle with rhythm almost in a strategic way, or they just want to treat every battle like it's their last one thing stays the same they will always think, The show must go on!    

Rhythm Of Your Soul

Starting when you chose this subclass at the 3rd level: You find whenever you hear music it is easier to work your magic. If you hear any type of music you now have an advantage on ability checks and saving throws, however, you need to hear it, if you have the deafened effect this doesn't apply until the affliction is lifted.

Examples:

1. The bard in your party starts playing a song and you are appeased to hear it, it fuels your ability to not be mind-controlled.
2. You're having a drinking contest with someone in a tavern, a group of performers begins to play, you feel motivated to win that contest.
3. Despite all the music that is being played a strange spell prohibits you to hear it, you can't get the motivation you'd usually feel.

The Art Of Your Battle

At level 3: With your time learning your art, you've created three dances that are able to shift combat in your favor. on your turn, you can use a bonus action to activate one of these strange movements which will continue until you drop it using an action or your movement is stopped or slowed. Once you have dropped Dance you can use a bonus action to activate another:

• The Unpredictable Sway: Matching your movements to the strange rhythm you hear within your mind, causes you to sway and turn in strange ways, while you have this active, all creatures have disadvantage on attack rolls made against you, however, you have disadvantage on attack rolls made against any creature. Additionally, if a creature misses any attacks against you in this form you gain an opportunity attack upon the creature (which you can add your sneak attack bonus to).
• The Flamboyant Sway: Using your "questionable" choices of dance you strut and stride your way through the fight making it so all eyes are on you, when you have this active, you add your performance skill to all attack checks, however, because of the reckless strut you trigger opportunity attacks when leaving and entering enemies attack ranges. Additionally, if you roll a natural 20 against a creature you get an extra attack. 
• The Elegant Sway: Using your elegance throughout the battle creating a visage no one can look away from, when you activate this sway, you no longer trigger opportunity attacks, and any enemy you pass by must make a Wisdom saving throw (DC:8+prof+cha) or be stunned until the end of their next turn, you move 5ft away from them, or you drop the sway, however on a successful save if you are within their range they get an opportunity attack on you with advantage. Additionally, any allies within 5ft can add their performance skill to an attack roll (Minumum of  +1).

If any of these sways come to a complete halt without you ending them with an action (your speed is halved or reaches zero), you have disadvantage on all checks and saving throws until the beginning of your next turn.

The Show Must Go On!

Upon reaching 9th level: When an ally is incapacitated within range of motion, using your reaction you dash forward towards your falling ally, upon this you can bring them back into the battle at 1hp+temparary hit points equal to your performance skill, you can use this ability once before taking long rest.

Unbreakable Stride!

Upon reaching level 13: Once per day, you can make any attack or grapple made upon you (unless it is a natural 20 on the role/check, also magic missile still applies) automatically miss until the beginning of your next turn. Additionally, you automatically succeed any Dexterity or Strength saving throws.

All Out Preformance!

Upon reaching level 17: On your turn, you can use an action to hear your most favored song playing within your mind, for the next minute, you can add your performance modifier to ALL rolls including damage, additionally, if you make an attack, upon that attack landing regardless of the circumstance you gain your sneak attack bonus. As a final note, you can spend a reaction to add your performance skill to a allies role (unless there incapacitated)