I am not sure that I like the idea of a reset that can only work against me...kind of feels like the game is "cheating" that way. The sense of loss is there because of the build up when playing the previous match, and that sense of loss makes a player feel uncomfortable even if they do not know why they feel uncomfortable--although, I think most would understand what makes them feel out of sorts with the game at that point.
A better method, I think, would be to give a little bit of swing either way. For example, you can go into the next match with a negative balance of powers, or a positive balance of powers but the % that is able to carry over to the next round (positive or negative in number) would be set. So, if you set it at 30%, then someone who starts with all stats at 10 in round one could possibly gain or lose (reward/punishment principle) up to 3 stat points on each stat depending upon where they left off at when match 1 ends. If they were ahead by more than 5 stat points, they get to keep 30% of those points which would be seen as a reward for successfully adding those points during the previous match...it would always be based upon the starting score of the match. %'s would them be more evenly balanced based upon the card choosing skills of the player, rather than luck...I think...lol