The idea of combining dynamic perks as cards seems promising, I like it, although I had some trouble regarding to the interface. Why not to use a few keys in a row (for example: 1, 2, 3, 4)? League of Legends style. I think this game would work best if something like that, combined with the arrow keys, was implemented. I just found myself a bit lost in between E, Z and K.
The aesthetic is good, so I think it is more about polishing the way you input commands than the gameplay on itself, which is simple and concise (dodge and hit when you can).
I would also add a bit more feedback to the interface, as it took me a while to learn that by pressing space I was going back to fight. It would be a great idea to add some kind of counter to the coldown cards, instead of waiting them to shine, so the player can use such information to anticipate his moves. Same with choosing cards; was I meant to chose them, or they were just displayed before the match? I think this idea has potential, it just needs a bit more polishing. But great work! It's eye candy.