KO someone with a Super Attack to complete this challenge. If you are having a difficult time with Super attacks, they can be practiced in training mode. (Read the move lists!)
This achievement can also be earned in a local match so you don't have to worry about your opponent's counter/parry/dodge/block or otherwise messing up your efforts.
*NOTE: Local matches are an easy way to get "EX-ceptional", "Big Finish", "Wax On, Wax Off", and "Sticks and Stones". Don't bother with "Super Artist" in this mode (unless you're really stuck) because it is time consuming.