Hello, I have ompleted all the base game achievements for Ghostrunner now and the solution to this one is simply loading up the map "things you wouldn't believe".
Pick both tempest upgrades + the one with focus regen, wait for your tempest to charge and run to the first encounter with the little volatile enemies, you can spam tempest as long as you kill two or more enemies at once, after you cleared them all you restart the level and NOT THE CHECKPOINT!
you need to do this twice and you got the achievement, just don't die on the way there with the wallruns.
This information is widely accessible through steam guides or Youtube and not mine originally! I just pass it on because there was no guide here on the site.