CotS: One Minute Martial Arts

I'm currently working on a new setting that I'm tentatively calling Children of the Sun.  Unlike my other games, where the focus is on keeping power levels low and manageable, especially when it comes to player-characters, this new setting is intended to be more like a shounen anime or a wire-fu martial arts movie.  Sort of like a mash-up between Crouching Tiger, Hidden Dragon and Fist of the North Star.  

As such, I really wanted to sell the idea that the players were badasses who were well-trained in combat.  As such, I cooked up a new combat system that seems to work pretty well.  It might not fit all games, but I think it conveys that idea well enough.

                                          both images are from Weak Hero

Martial Arts and Combat Reflexes:

When making an attack, the attacker should roll 1d20+Atk and his damage di(c)e+Atk and declare the result of both rolls. 

Then the defender should choose whether they want to Dodge or Block.

Dodge means the defender rolls 1d20+Atk and pits it against the attacker's 1d20+atk.  If the defender rolls higher, he wins and takes no damage.  If he rolls lower, he takes full damage.  If there is a tie, the defender wins.

Block means that the defender rolls his damage dice and pits it against the attackers's damage dice.  In this situation, whoever rolls higher wins and the loser takes damage equal to the difference in damage between winner and loser.  If both sides roll damage equal to their number, neither take damage.

Twin Examples:

Dodge-

Bob is attacking Alice.

Bob rolls 1d20(19)+Atk(1)= 20 and 1d6(6)+Atk(1)= 7

Alice decides to Dodge.

Alice rolls 1d20(8)+Atk(4)= 12

Since Bob rolled higher, he wins the contest and hits Alice, dealing 7 damage.

Block-

Alice counter-attacks Bob.

Alice rolls 1d20(2)+Atk(4)= 6 and 1d6(5)+Atk(4)= 11

Bob decides to Block. 

Bob rolls 1d6(3)+Atk(1)= 4

Since Alice rolled higher, she wins the contest and Bob takes 7 damage.