5e feat: Rythmic Combat

[clash]

Thoughts on this feat for a dervish style character?

Rythmic Combat:
You have a a rythmic style of fighting where you unleash a barrage of attacks on your for ending with a single decisive strike.
* Whenever you hit a creature with a light melee weapon or an unarmed strike you may choose to deal an additional d6 of damage to the creature for each attack you already made against the same creature with a light melee weapon or unarmed strike this turn. If you do you can make no more attacks this turn.
* If you are unarmored or wearing light armor and not using a shield whenever a creature misses you with an attack you gain a +2 bonus to ac until the end of your next turn.

[TemporalTravels]

Thoughts on this feat for a dervish style character?

Rythmic Combat:
You have a a rythmic style of fighting where you unleash a barrage of attacks on your for ending with a single decisive strike.
* Whenever you hit a creature with a light melee weapon or an unarmed strike you may choose to deal an additional d6 of damage to the creature for each attack you already made against the same creature with a light melee weapon or unarmed strike this turn. If you do you can make no more attacks this turn.
* If you are unarmored or wearing light armor and not using a shield whenever a creature misses you with an attack you gain a +2 bonus to ac until the end of your next turn.

This reads as, not including Strength bonuses:

2nd level fighter with a short sword
First attack (1d6)
Action surge
Second attack (1d6)
Activate feat (+2d6 guaranteed - verbiage says # of attacks previously made and not attacks that hit) = up to 4d6 on a target

Or on average
First attack (1d6)
Activate feat (+1d6) = 2d6 ... avg 7 HP

5th level fighter with a short sword
First attack action (2d6)
Action surge
Second attack action (2d6)
Activate feat (+4d6 guaranteed) = up to 8d6 on a target

Or on average
First attack action (2d6)
Activate feat (+2d6 guaranteed) = 4d6 ... avg 14 HP

You'll have to measure that against your typical monster HP.

[GalacticAxekick]

Setting aside the question of whether or not this is balanced, this feat looks needlessly complicated.

If the goal is to make a feat that says "you deal more damage when you focus on one enemy" just represent that as simply as possible.

"When you make your first attack on your turn, you can decide to focus on one enemy that you can see. Doing so makes your light weapon attacks and unarmed strikes deal an extra 1d4 damage during this turn, but prevents you from attacking any other target during this turn."



EDIT: The second effect of the feat, by the way, is overpowered. It's a reaction-free +2 bonus to AC for a whole round if you are missed with a single attack. The Defensive Duelist feat, for reference, starts as a +2 bonus to AC against one attack as a reaction.

This second effect should probably be its own feat, and should cost a reaction. I think it's fine if it's better than Defensive Duelist (because DD isn't really good anyway), but it shouldn't be free or bundled with the 50% damage boost that you've bundled it with.