Only done to pass the rank 19 easily

Whrilwind and [Rebound] to ranged killing.

Stay as possible near the spawn_point. Don't jump, take your time. You can kill 7 ennemies before begin to walking on the map.
I recommand you to begin on the right side. A grineer patrol behind the first ramp, it's the biggest trap from this map. If you crouch and go to the right ramp, you can kill him without problem. Continue to the right, kill the guy on the hightest central platform behind the prisonner cage, continue to finish with the guy you can see far far away on the bottom of your screen.

DE has corrected the "crouch bug" that permits ennemies to don't see you when you crouch. So you can't pass this test like a skyrim thief anymore.

Break luminous bubbles only when all ennemies had been killed.