I've come pretty late to the party but I've found that the best way to come out on top in any Tron: Evolution game type is to never ever stop moving and continually pester your foes with power and charged attacks, only jump into up close and personal engagements when the enemy is distracted or their heath is low and you know that you can win, and to bombard them from afar.
I find that the easiest way to rack up derezzes whilst keeping your wipe count low is to create a route in which you traverse the map. Select a pattern or route with abundant health and energy conduits, this will keep you alive and on the move, as well as fully charged when the chance to strike at the enemy presents itself. Your ever changing position will also confuse the enemy when they try to attack you, and in most cases I find that the other players down right ignore me when I vault across the map and away from them. A fatal mistake as my carefully planned route brings me right back around to them fully charged and ready to open a can of whoop-ass.
Also, wait to strike until multiple enemies have worn each other down, and then Derezz them all at once with a single Heavy Disk Blossom (RT & Y) or a Bomb Disc Boomzer (RT & Y). Make your enemies work for you.
Basically, never stop moving, never jump head first into a fight, stay on top of your heath and energy levels, and always use high powered energy attacks and this achievement will be yours.