Simple way to get this is to play the Terror Trial challenge stage repeatedly. It is an easy trial, just use force repulse for the spiders, then shock the Terror Troopers with lighting and hack them to bits. Repeat the trial and get at least a bronze medal and but don't die otherwise the achievement resets.
You get 81 kills a trial, so after 5 goes the achievement unlocks.
It helps if force repulse and lightning are upgraded but can be done without.